diff --git a/frontend/scripts/regression-dataset-preview.mjs b/frontend/scripts/regression-dataset-preview.mjs
index 8a339ac..de14357 100644
--- a/frontend/scripts/regression-dataset-preview.mjs
+++ b/frontend/scripts/regression-dataset-preview.mjs
@@ -10,6 +10,7 @@ const previewComponentPaths = [
   'DatasetRecordTable.vue',
   'DatasetRecordEditorDialog.vue',
   'DatasetRawPreview.vue',
+  'DatasetSplitNavigator.vue',
 ].map((name) => path.join(previewComponentsDir, name))
 const apiPath = path.join(root, 'src/api/modules/dataset.ts')
 const adapterPath = path.join(root, 'src/mock/adapter.ts')
@@ -50,12 +51,16 @@ function expect(condition, message) {
 }
 
 expect(previewLogicSource.split('\n').length < 520, 'DatasetPreviewView.vue 的逻辑与模板应保持在 520 行以内')
-for (const componentName of ['DatasetVersionBar', 'DatasetRecordTable', 'DatasetRecordEditorDialog', 'DatasetRawPreview']) {
+for (const componentName of ['DatasetVersionBar', 'DatasetRecordTable', 'DatasetRecordEditorDialog', 'DatasetRawPreview', 'DatasetSplitNavigator']) {
   expect(source.includes(`import ${componentName}`), `主页面未导入叶子组件：${componentName}`)
   expect(source.includes(`<${componentName}`), `主页面未挂载叶子组件：${componentName}`)
 }
 expect(source.includes('class="preview-workspace"'), '详情页应提供数据文件工作区')
-expect(!source.includes('class="file-pane"'), '单文件数据集详情不应展示文件选择侧栏')
+expect(previewSurfaceSource.includes('class="split-file-tabs"'), '多切分数据集应提供训练/验证/测试文件切换')
+expect(source.includes('@select="handleFileChange"'), '切换数据切分时应加载对应文件版本')
+expect(previewSurfaceSource.includes('splitCounts.train'), '数据集概览应显示训练集数量')
+expect(previewSurfaceSource.includes('splitCounts.validation'), '数据集概览应显示验证集数量')
+expect(previewSurfaceSource.includes('splitCounts.test'), '数据集概览应显示测试集数量')
 expect(previewSurfaceSource.includes('class="code-line"'), '内容查看器应提供逐行展示')
 expect(previewSurfaceSource.includes('class="line-number"'), '内容查看器应显示行号')
 expect(source.includes('previewLoading'), '切换文件时应提供独立加载状态')
diff --git a/frontend/src/types/index.ts b/frontend/src/types/index.ts
index 9405842..e64cc66 100644
--- a/frontend/src/types/index.ts
+++ b/frontend/src/types/index.ts
@@ -63,6 +63,8 @@ export interface DatasetFile {
   id?: string
   name: string
   size?: string | number
+  record_count?: number
+  split?: 'train' | 'validation' | 'test' | null
   [k: string]: any
 }
 
@@ -78,6 +80,7 @@ export interface DatasetItem {
   description?: string
   create_time?: string
   files?: DatasetFile[]
+  split_counts?: { train: number; validation: number; test: number }
 }
 
 export interface DatasetVersion {
diff --git a/frontend/src/views/data-process/DataProcessDetailView.vue b/frontend/src/views/data-process/DataProcessDetailView.vue
index b81a371..d881276 100644
--- a/frontend/src/views/data-process/DataProcessDetailView.vue
+++ b/frontend/src/views/data-process/DataProcessDetailView.vue
@@ -448,6 +448,33 @@ async function publishDataset() {
   }
 }
 
+async function resyncPublishedDataset() {
+  if (!detail.value || !outputDatasetId.value || publishing.value) return
+  try {
+    await ElMessageBox.confirm(
+      '将按当前 8:1:1 配置重新生成训练、验证、测试三个切分文件，数据集 ID 保持不变。',
+      '重新同步数据切分？',
+      { type: 'warning', confirmButtonText: '重新同步', cancelButtonText: '取消' },
+    )
+  } catch {
+    return
+  }
+
+  publishing.value = true
+  try {
+    const published = await publishDataProcess(taskId.value, {
+      ...publishForm,
+      dataset_name: outputDatasetName.value || `${detail.value.name}-数据集`,
+      split: configuredSplit(),
+    })
+    ElMessage.success('训练集、验证集和测试集已重新同步')
+    const datasetId = published.dataset?.id || outputDatasetId.value
+    await router.push(`/dataset/${datasetId}/preview`)
+  } finally {
+    publishing.value = false
+  }
+}
+
 watch([currentPage, pageSize], () => void loadResults())
 
 onMounted(loadPage)
@@ -472,6 +499,13 @@ onBeforeUnmount(() => {
             <i class="fa" :class="outputDatasetId ? 'fa-external-link' : 'fa-database'" />
             {{ outputDatasetId ? '查看输出数据集' : '发布为数据集' }}
           </el-button>
+          <el-button
+            v-if="detail.status === 'completed' && outputDatasetId"
+            :loading="publishing"
+            @click="resyncPublishedDataset"
+          >
+            <i class="fa fa-refresh" />重新同步切分
+          </el-button>
         </div>
         <p>{{ detail.description || '暂无任务描述' }}</p>
         <dl class="heading-meta">
@@ -717,7 +751,7 @@ onBeforeUnmount(() => {
       <el-alert
         type="info"
         :closable="false"
-        :title="`数据集划分：训练集 ${publishForm.split.train}% / 验证集 ${publishForm.split.validation}% / 测试集 ${publishForm.split.test}%`"
+        :title="`将生成三个独立文件：训练集 ${publishForm.split.train}% / 验证集 ${publishForm.split.validation}% / 测试集 ${publishForm.split.test}%`"
       />
     </el-form>
     <template #footer>
diff --git a/frontend/src/views/dataset/DatasetListView.vue b/frontend/src/views/dataset/DatasetListView.vue
index 2f2ab79..dd4ee29 100644
--- a/frontend/src/views/dataset/DatasetListView.vue
+++ b/frontend/src/views/dataset/DatasetListView.vue
@@ -21,6 +21,17 @@ const filteredDataList = computed(() => {
   return dataList.value.filter((item) => item.source !== 'task')
 })
 
+const splitLabels = [
+  { key: 'train', label: '训练', type: 'primary' },
+  { key: 'validation', label: '验证', type: 'warning' },
+  { key: 'test', label: '测试', type: 'success' },
+] as const
+
+function hasSplitCounts(row: Partial<DatasetItem>) {
+  return row.source === 'task'
+    && Object.values(row.split_counts || {}).some((value) => Number(value) > 0)
+}
+
 async function loadData() {
   loading.value = true
   try {
@@ -87,9 +98,17 @@ onMounted(loadData)
       <el-table-column label="数据集名称" prop="name" align="center" />
       <el-table-column label="数据类型" align="center" width="110">
         <template #default="{ row }">
-          <el-tag type="primary" size="small">
-            {{ DATASET_TYPE_MAP[String(row.type).toLowerCase()] || row.type || '-' }}
-          </el-tag>
+          <div v-if="hasSplitCounts(row)" class="split-tags">
+            <el-tag
+              v-for="item in splitLabels"
+              :key="item.key"
+              :type="item.type"
+              size="small"
+            >
+              {{ item.label }} {{ row.split_counts?.[item.key] || 0 }}
+            </el-tag>
+          </div>
+          <el-tag v-else type="primary" size="small">{{ DATASET_TYPE_MAP[String(row.type).toLowerCase()] || row.type || '-' }}</el-tag>
         </template>
       </el-table-column>
       <el-table-column label="存储位置" align="center" width="110">
@@ -167,4 +186,11 @@ onMounted(loadData)
     font-weight: 600;
   }
 }
+
+.split-tags {
+  display: flex;
+  flex-wrap: wrap;
+  justify-content: center;
+  gap: 4px;
+}
 </style>
diff --git a/frontend/src/views/dataset/DatasetPreviewView.vue b/frontend/src/views/dataset/DatasetPreviewView.vue
index db45d03..f9aa3f3 100644
--- a/frontend/src/views/dataset/DatasetPreviewView.vue
+++ b/frontend/src/views/dataset/DatasetPreviewView.vue
@@ -20,6 +20,7 @@ import DatasetVersionBar from './preview/DatasetVersionBar.vue'
 import DatasetRecordTable from './preview/DatasetRecordTable.vue'
 import DatasetRecordEditorDialog from './preview/DatasetRecordEditorDialog.vue'
 import DatasetRawPreview from './preview/DatasetRawPreview.vue'
+import DatasetSplitNavigator from './preview/DatasetSplitNavigator.vue'
 import type { EditField } from './preview/types'
 import type { DatasetFile, DatasetItem, DatasetVersion } from '@/types'
 
@@ -53,6 +54,7 @@ let versionRequestId = 0
 
 const files = computed<DatasetFile[]>(() => dataset.value?.files || [])
 const selectedFile = computed(() => files.value.find((file) => fileKey(file) === selectedFileId.value))
+const splitCounts = computed(() => dataset.value?.split_counts || { train: 0, validation: 0, test: 0 })
 const totalLines = computed(() => previewContent.value ? previewContent.value.split('\n').length : 0)
 const recordResult = computed(() => parseDatasetRecords(previewContent.value, selectedFile.value?.name || ''))
 const isRecordFile = computed(() => recordResult.value.supported)
@@ -81,6 +83,13 @@ function fileKey(file: DatasetFile) {
   return String(file.id || file.name)
 }
 
+async function handleFileChange(file: DatasetFile) {
+  if (fileKey(file) === selectedFileId.value) return
+  if (!await confirmDiscardChanges('切换数据切分后，当前样本的未保存修改将丢失。')) return
+  selectedFileId.value = fileKey(file)
+  await loadVersions(file)
+}
+
 async function loadDataset() {
   loading.value = true
   try {
@@ -400,6 +409,12 @@ onBeforeUnmount(() => window.removeEventListener('beforeunload', handleBeforeUnl
       <div class="overview-item overview-item-wide"><span>创建时间</span><strong>{{ createdAt }}</strong></div>
     </section>
 
+    <DatasetSplitNavigator
+      v-if="Object.values(splitCounts).some((value) => value > 0)"
+      :files="files" :selected-file-id="selectedFileId" :split-counts="splitCounts"
+      @select="handleFileChange"
+    />
+
     <DatasetVersionBar
       v-model="selectedVersionId"
       :versions="versions"
@@ -488,10 +503,7 @@ onBeforeUnmount(() => window.removeEventListener('beforeunload', handleBeforeUnl
     </section>
 
     <DatasetRecordEditorDialog
-      :model-value="editorVisible"
-      :record="editingRecord"
-      :edit-fields="editFields"
-      :raw-draft="rawDraft"
+      :model-value="editorVisible" :record="editingRecord" :edit-fields="editFields" :raw-draft="rawDraft"
       :saving-record="savingRecord"
       :has-draft-changes="hasEditorDraftChanges"
       :next-version-number="nextVersionNumber"
@@ -500,7 +512,6 @@ onBeforeUnmount(() => window.removeEventListener('beforeunload', handleBeforeUnl
       @update:field="updateEditField"
       @update:raw-draft="rawDraft = $event"
     />
-
     <AppConfirmDialog ref="confirmDialogRef" />
   </PageCard>
 </template>
diff --git a/frontend/src/views/dataset/preview/DatasetSplitNavigator.vue b/frontend/src/views/dataset/preview/DatasetSplitNavigator.vue
new file mode 100644
index 0000000..0a17a6d
--- /dev/null
+++ b/frontend/src/views/dataset/preview/DatasetSplitNavigator.vue
@@ -0,0 +1,103 @@
+<script setup lang="ts">
+import type { DatasetFile } from '@/types'
+
+defineProps<{
+  files: DatasetFile[]
+  selectedFileId: string
+  splitCounts: { train: number; validation: number; test: number }
+}>()
+
+const emit = defineEmits<{ select: [file: DatasetFile] }>()
+
+function fileKey(file: DatasetFile) {
+  return String(file.id || file.name)
+}
+
+function splitLabel(split?: DatasetFile['split']) {
+  if (!split) return '数据文件'
+  return { train: '训练集', validation: '验证集', test: '测试集' }[split]
+}
+
+function splitTagType(split?: DatasetFile['split']) {
+  if (!split) return 'info'
+  return ({ train: 'primary', validation: 'warning', test: 'success' } as const)[split]
+}
+</script>
+
+<template>
+  <section class="split-summary" aria-label="数据切分统计">
+    <div class="split-stat train"><span>训练集</span><strong>{{ splitCounts.train.toLocaleString() }}</strong></div>
+    <div class="split-stat validation"><span>验证集</span><strong>{{ splitCounts.validation.toLocaleString() }}</strong></div>
+    <div class="split-stat test"><span>测试集</span><strong>{{ splitCounts.test.toLocaleString() }}</strong></div>
+  </section>
+
+  <nav v-if="files.length > 1" class="split-file-tabs" aria-label="数据切分文件">
+    <button
+      v-for="file in files"
+      :key="fileKey(file)"
+      type="button"
+      class="split-file-tab"
+      :class="{ active: fileKey(file) === selectedFileId }"
+      @click="emit('select', file)"
+    >
+      <el-tag :type="splitTagType(file.split)" size="small">{{ splitLabel(file.split) }}</el-tag>
+      <strong>{{ (file.record_count || 0).toLocaleString() }} 条</strong>
+      <span>{{ file.name }}</span>
+    </button>
+  </nav>
+</template>
+
+<style scoped lang="scss">
+.split-summary,
+.split-file-tabs {
+  display: grid;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  gap: 10px;
+  margin-bottom: 14px;
+}
+
+.split-stat {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 12px 16px;
+  border: 1px solid #e5eaf2;
+  border-radius: 10px;
+  background: #fbfcfe;
+  color: #667085;
+}
+
+.split-stat strong { font-size: 18px; }
+.split-stat.train strong { color: #4f46e5; }
+.split-stat.validation strong { color: #d97706; }
+.split-stat.test strong { color: #059669; }
+
+.split-file-tab {
+  display: grid;
+  grid-template-columns: auto auto 1fr;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
+  padding: 12px 14px;
+  border: 1px solid #e5eaf2;
+  border-radius: 10px;
+  background: #fff;
+  color: #344054;
+  cursor: pointer;
+  text-align: left;
+}
+
+.split-file-tab:hover,
+.split-file-tab.active {
+  border-color: #818cf8;
+  background: #f7f7ff;
+}
+
+.split-file-tab span:last-child {
+  overflow: hidden;
+  color: #8a94a6;
+  font-size: 12px;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+</style>