diff --git a/apps/web/src/admin/problem/components/CodePreview.vue b/apps/web/src/admin/problem/components/CodePreview.vue
index fe6d743..4e70cdb 100644
--- a/apps/web/src/admin/problem/components/CodePreview.vue
+++ b/apps/web/src/admin/problem/components/CodePreview.vue
@@ -27,6 +27,8 @@ const props = defineProps<{
   examples: { input: string; output: string }[]
   /** 例子来自哪几组，比如「测试数据第 1–4 组」 */
   examplesNote: string
+  /** 测试数据太大不展开、例子单独写的时候 */
+  bigData?: boolean
   languages: LANGUAGE[]
   templates: Partial<Record<LANGUAGE, TemplateParts>>
   astRules: AstRules | null
@@ -196,7 +198,9 @@ onMounted(() => nextTick(render))
           <pre class="sampleCell" role="cell">{{ sample.output }}</pre>
         </template>
       </div>
-      <p v-else class="placeholder">在左边的测试数据里勾几组「当例子」</p>
+      <p v-else class="placeholder">
+        {{ bigData ? "在左边加一个例子" : "在左边的测试数据里勾几组「当例子」" }}
+      </p>
 
       <template v-if="!isBlankHtml(hint)">
         <h3 class="title">提示</h3>
diff --git a/apps/web/src/admin/problem/components/caseRows.ts b/apps/web/src/admin/problem/components/caseRows.ts
index 073844d..b2146f8 100644
--- a/apps/web/src/admin/problem/components/caseRows.ts
+++ b/apps/web/src/admin/problem/components/caseRows.ts
@@ -49,6 +49,17 @@ export function newRow(input = "", output = "", example = false, saved: string |
   } satisfies CaseRow
 }
 
+/**
+ * 测试点文件读回来时的样子：CRLF 统一成 LF，输入去掉末尾那一个换行（文件里都有，摆在输入框里
+ * 就是多出来的一行空白；上传时 caseFiles 会补回去），输出去掉末尾空白（判题机比对时本来就不看）
+ */
+export function normalizeCase(input: string, output: string) {
+  return {
+    input: input.replace(/\r\n/g, "\n").replace(/\n$/, ""),
+    output: output.replace(/\r\n/g, "\n").trimEnd(),
+  }
+}
+
 /** 判题机比对时去掉的是整段输出末尾的空白（见 services/test-case.ts 的 rstrip），这里同一个口径 */
 export function sameOutput(a: string, b: string) {
   return a.replace(/\r\n/g, "\n").trimEnd() === b.replace(/\r\n/g, "\n").trimEnd()
@@ -171,7 +182,7 @@ export function readCaseZip(
       output.length > TEST_CASE_EDIT_MAX_FILE_BYTES
     )
       return { ok: false, reason: "too-large" }
-    cases.push({ input: strFromU8(input), output: strFromU8(output) })
+    cases.push(normalizeCase(strFromU8(input), strFromU8(output)))
   }
   if (!cases.length)
     return { ok: false, reason: "压缩包里没有从 1.in / 1.out 开始连续编号的测试点" }
diff --git a/apps/web/src/admin/problem/detail.vue b/apps/web/src/admin/problem/detail.vue
index a116c9e..e365fec 100644
--- a/apps/web/src/admin/problem/detail.vue
+++ b/apps/web/src/admin/problem/detail.vue
@@ -26,6 +26,7 @@ import {
   caseFiles,
   caseStatus,
   newRow,
+  normalizeCase,
   readCaseZip,
   sameOutput,
   useCaseRunner,
@@ -343,6 +344,8 @@ async function importZip({ file }: UploadCustomRequestOptions) {
     return
   }
   try {
+    // 先把现在的例子拿下来：big 一设上，examples 就改读 exampleRows 了
+    const keep = examples.value
     const res = await uploadTestcases(raw)
     setTestCase(res.id, res.info)
     big.value = {
@@ -350,7 +353,7 @@ async function importZip({ file }: UploadCustomRequestOptions) {
       totalBytes: res.info.reduce((sum, e) => sum + e.input_size + e.output_size, 0),
     }
     if (!exampleRows.value.length) {
-      exampleRows.value = examples.value.map((e) => newRow(e.input, e.output, true))
+      exampleRows.value = keep.map((e) => newRow(e.input, e.output, true))
     }
     rows.value = []
     loadedCases = null
@@ -604,8 +607,8 @@ async function loadProblem(data: AdminProblem) {
     exampleRows.value = data.samples.map((s) => newRow(s.input, s.output, true, s.output))
     return
   }
-  loadedCases = files.cases
-  rows.value = files.cases.map((c) => newRow(c.input, c.output, false, c.output))
+  loadedCases = files.cases.map((c) => normalizeCase(c.input, c.output))
+  rows.value = loadedCases.map((c) => newRow(c.input, c.output, false, c.output))
   // 例子对回测试数据：输入一样的那组勾上；对不上的（老题的例子多半不在测试数据里）补到最后
   let appended = 0
   for (const sample of data.samples) {
@@ -658,7 +661,12 @@ const blockers = computed<Blocker[]>(() => {
   if (!source.value && caseRows.some((r) => !r.output.trim()))
     list.push({ text: "补上没写的输出", section: "cases" })
   if (!examples.value.length)
-    list.push({ text: "勾一组当例子（题面上至少给学生一个）", section: "cases" })
+    list.push({
+      text: big.value
+        ? "加一个例子（题面上至少给学生一个）"
+        : "勾一组当例子（题面上至少给学生一个）",
+      section: "cases",
+    })
 
   for (const [lang, state] of Object.entries(astChecks.value)) {
     if (!form.languages.includes(lang as RunnableLanguage)) continue
@@ -1007,7 +1015,7 @@ onMounted(async () => {
               <n-button size="tiny" quaternary>导入 zip</n-button>
             </n-upload>
             <n-button
-              v-if="!big ? rows.length : !!initial"
+              v-if="!big ? rows.length : !!initial && testCase.id === initial.testCaseId"
               size="tiny"
               quaternary
               @click="downloadZip"
@@ -1276,6 +1284,7 @@ onMounted(async () => {
       :hint="form.hint"
       :examples="examples"
       :examples-note="examplesNote"
+      :big-data="!!big"
       :languages="form.languages"
       :templates="templatesForPreview"
       :ast-rules="form.astRules"