diff --git a/src/api/admin/competitions.ts b/src/api/admin/competitions.ts
index 63b2bac..ba9e511 100644
--- a/src/api/admin/competitions.ts
+++ b/src/api/admin/competitions.ts
@@ -69,7 +69,8 @@ export async function createCompetition(payload: CompetitionPayload): Promise<Co
 }
 
 export async function updateCompetition(id: number, payload: CompetitionPayload): Promise<CompetitionRow> {
-  const { data } = await adminHttp.put<unknown>(`/competitions/${id}`, payload)
+  // 正式环境部分网关会挂起 PUT，改用 PATCH
+  const { data } = await adminHttp.patch<unknown>(`/competitions/${id}`, payload)
   const body = (data as { data?: CompetitionRow })?.data ?? (data as CompetitionRow)
   if (!body || typeof body !== 'object') throw new Error('更新响应无效')
   return body as CompetitionRow
diff --git a/src/utils/datetimeShanghai.ts b/src/utils/datetimeShanghai.ts
new file mode 100644
index 0000000..6f4950d
--- /dev/null
+++ b/src/utils/datetimeShanghai.ts
@@ -0,0 +1,63 @@
+/** 业务时间统一按北京时间（Asia/Shanghai，无夏令时）处理。 */
+
+const SHANGHAI = 'Asia/Shanghai'
+
+function pad(n: number): string {
+  return String(n).padStart(2, '0')
+}
+
+/**
+ * API ISO / 任意可解析时间 → 日期时间选择器模型（北京时间 `YYYY-MM-DD HH:mm:ss`）。
+ */
+export function toShanghaiPickerValue(iso: string | null | undefined): string | null {
+  if (!iso) return null
+  const d = new Date(iso)
+  if (Number.isNaN(d.getTime())) return null
+
+  const parts = new Intl.DateTimeFormat('en-GB', {
+    timeZone: SHANGHAI,
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+    hour: '2-digit',
+    minute: '2-digit',
+    second: '2-digit',
+    hourCycle: 'h23',
+  }).formatToParts(d)
+
+  const get = (type: Intl.DateTimeFormatPartTypes): string =>
+    parts.find((p) => p.type === type)?.value ?? '00'
+
+  const hour = get('hour') === '24' ? '00' : get('hour')
+  return `${get('year')}-${get('month')}-${get('day')} ${hour}:${get('minute')}:${get('second')}`
+}
+
+/**
+ * 选择器值（按北京时间理解）→ API ISO8601（带偏移，避免被当成 UTC）。
+ */
+export function fromShanghaiPickerValue(s: string | null | undefined): string | null {
+  const t = (s ?? '').trim()
+  if (!t) return null
+  const m = t.match(/^(\d{4})-(\d{2})-(\d{2})[ T](\d{2}):(\d{2})(?::(\d{2}))?/)
+  if (!m) return null
+  const [, y, mo, d, h, mi, sec = '00'] = m
+  return `${y}-${mo}-${d}T${h}:${mi}:${sec}+08:00`
+}
+
+/** 列表/详情展示用北京时间。 */
+export function formatShanghaiDateTime(iso: string | null | undefined, empty = '—'): string {
+  const v = toShanghaiPickerValue(iso)
+  if (!v) return empty
+  return v.replace(/:\d{2}$/, '') // YYYY-MM-DD HH:mm
+}
+
+export function formatShanghaiDateTimeFull(iso: string | null | undefined, empty = '—'): string {
+  return toShanghaiPickerValue(iso) ?? empty
+}
+
+/** 调试/校验用 */
+export function shanghaiOffsetLabel(): string {
+  return `${SHANGHAI} (UTC+8)`
+}
+
+export { pad }
diff --git a/src/views/admin/AdminDashboardView.vue b/src/views/admin/AdminDashboardView.vue
index 624d58a..9d35994 100644
--- a/src/views/admin/AdminDashboardView.vue
+++ b/src/views/admin/AdminDashboardView.vue
@@ -10,6 +10,7 @@ import type {
 } from '../../api/admin/types'
 import { useAdminCompetitionStore } from '../../stores/adminCompetition'
 import { competitionStatusLabel } from '../../utils/competitionAdminLabels'
+import { formatShanghaiDateTime } from '../../utils/datetimeShanghai'
 
 type SetupKey = keyof AdminDashboardSetup
 
@@ -147,8 +148,7 @@ async function loadDashboard() {
 
 function formatDateTime(value: string | null | undefined): string {
   if (!value) return '未配置'
-  const d = new Date(value)
-  return Number.isNaN(d.getTime()) ? value : d.toLocaleString()
+  return formatShanghaiDateTime(value, '未配置')
 }
 
 function statusTagType(status: string): 'success' | 'info' | 'warning' | 'danger' | 'primary' {
diff --git a/src/views/admin/competition/CompetitionFormView.vue b/src/views/admin/competition/CompetitionFormView.vue
index e3f8c02..d24ae89 100644
--- a/src/views/admin/competition/CompetitionFormView.vue
+++ b/src/views/admin/competition/CompetitionFormView.vue
@@ -15,6 +15,7 @@ import {
 } from '../../../api/admin/competitions'
 import * as formSchemaApi from '../../../api/admin/formSchemas'
 import { setSignupFieldRegistry } from '../../../utils/signupApplicationFields'
+import { fromShanghaiPickerValue, toShanghaiPickerValue } from '../../../utils/datetimeShanghai'
 import {
   createSignupChannel,
   getSignupChannel,
@@ -337,22 +338,14 @@ function resolveCompetitionId(): number | null {
   return sid && sid > 0 ? sid : null
 }
 
-/** API ISO → Element Plus 日期时间选择器（value-format `YYYY-MM-DD HH:mm:ss`，本地时区） */
+/** API ISO → Element Plus 日期时间选择器（北京时间 `YYYY-MM-DD HH:mm:ss`） */
 function toElDateTimeModel(iso: string | null | undefined): string | null {
-  if (!iso) return null
-  const d = new Date(iso)
-  if (Number.isNaN(d.getTime())) return null
-  const pad = (n: number) => String(n).padStart(2, '0')
-  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${pad(d.getHours())}:${pad(d.getMinutes())}:${pad(d.getSeconds())}`
+  return toShanghaiPickerValue(iso)
 }
 
+/** 选择器北京时间 → API（显式 +08:00，避免被当成 UTC 再偏移） */
 function fromDatetimePickerValue(s: string | null | undefined): string | null {
-  const t = (s ?? '').trim()
-  if (!t) return null
-  const forParse = t.includes('T') ? t : t.replace(/^(\d{4}-\d{2}-\d{2})\s+/, '$1T')
-  const d = new Date(forParse)
-  if (Number.isNaN(d.getTime())) return null
-  return d.toISOString()
+  return fromShanghaiPickerValue(s)
 }
 
 async function refreshSignupSchemas() {
diff --git a/src/views/admin/competition/CompetitionListView.vue b/src/views/admin/competition/CompetitionListView.vue
index 37339c3..e500267 100644
--- a/src/views/admin/competition/CompetitionListView.vue
+++ b/src/views/admin/competition/CompetitionListView.vue
@@ -4,6 +4,7 @@ import { ElMessage } from 'element-plus'
 import { listCompetitions } from '../../../api/admin/competitions'
 import type { CompetitionRow } from '../../../api/admin/types'
 import { competitionStatusLabel } from '../../../utils/competitionAdminLabels'
+import { formatShanghaiDateTime } from '../../../utils/datetimeShanghai'
 import { useAdminCompetitionStore } from '../../../stores/adminCompetition'
 
 const rows = ref<CompetitionRow[]>([])
@@ -37,9 +38,7 @@ function goPage(p: number) {
 }
 
 function formatDt(iso: string | null) {
-  if (!iso) return '—'
-  const d = new Date(iso)
-  return Number.isNaN(d.getTime()) ? iso : d.toLocaleString()
+  return formatShanghaiDateTime(iso)
 }
 
 onMounted(() => {