diff --git a/lib/__tests__/ding-workflow-sync.test.ts b/lib/__tests__/ding-workflow-sync.test.ts
index 5a10fb9..78b4ce1 100644
--- a/lib/__tests__/ding-workflow-sync.test.ts
+++ b/lib/__tests__/ding-workflow-sync.test.ts
@@ -1,5 +1,8 @@
 import {
+  DING_WORKFLOW_ALLOWED_PROCESS_CODES,
+  isAllowedDingWorkflowProcessCode,
   isDingWorkflowOngoing,
+  normalizeDingWorkflowProcessCode,
   sourceWorkflowTimestampToIso,
 } from '@/lib/ding-workflow-sync'
 
@@ -29,4 +32,21 @@ describe('ding workflow snapshot sync semantics', () => {
     expect(sourceWorkflowTimestampToIso('2026-08-20T10:30:00Z')).toBe('2026-08-20T10:30:00.000Z')
     expect(sourceWorkflowTimestampToIso('invalid')).toBeNull()
   })
+
+  it('only accepts the two approved process types', () => {
+    expect(DING_WORKFLOW_ALLOWED_PROCESS_CODES).toEqual([
+      'PROC-3571C915-0506-4490-A91A-8AA7EA33F838',
+      'PROC-AE9FF3E1-A442-4E6A-85CF-0F2B86409673',
+    ])
+    expect(isAllowedDingWorkflowProcessCode(' proc-3571c915-0506-4490-a91a-8aa7ea33f838 ')).toBe(true)
+    expect(isAllowedDingWorkflowProcessCode('PROC-AE9FF3E1-A442-4E6A-85CF-0F2B86409673')).toBe(true)
+    expect(isAllowedDingWorkflowProcessCode('PROC-OTHER')).toBe(false)
+    expect(isAllowedDingWorkflowProcessCode(null)).toBe(false)
+  })
+
+  it('normalizes process codes before persistence and comparison', () => {
+    expect(normalizeDingWorkflowProcessCode(' proc-ae9ff3e1-a442-4e6a-85cf-0f2b86409673 '))
+      .toBe('PROC-AE9FF3E1-A442-4E6A-85CF-0F2B86409673')
+    expect(normalizeDingWorkflowProcessCode('')).toBeNull()
+  })
 })
diff --git a/lib/ding-workflow-sync.ts b/lib/ding-workflow-sync.ts
index 1ea191d..404b75f 100644
--- a/lib/ding-workflow-sync.ts
+++ b/lib/ding-workflow-sync.ts
@@ -12,6 +12,13 @@ const DEFAULT_SYNC_INTERVAL_MS = 60 * 60 * 1000
 const INITIAL_SYNC_DELAY_MS = 5_000
 const UPSERT_BATCH_SIZE = 750
 
+export const DING_WORKFLOW_ALLOWED_PROCESS_CODES = [
+  'PROC-3571C915-0506-4490-A91A-8AA7EA33F838',
+  'PROC-AE9FF3E1-A442-4E6A-85CF-0F2B86409673',
+] as const
+const ALLOWED_PROCESS_CODE_VALUES: string[] = [...DING_WORKFLOW_ALLOWED_PROCESS_CODES]
+const ALLOWED_PROCESS_CODE_SET = new Set<string>(DING_WORKFLOW_ALLOWED_PROCESS_CODES)
+
 const WORKFLOW_TABLE = {
   schema: process.env.REPORT_DB_WORKFLOW_SCHEMA || 'rpt',
   table: process.env.REPORT_DB_WORKFLOW_TABLE || 'ding_Workflow',
@@ -129,6 +136,15 @@ function clean(value: unknown): string | null {
   return normalized || null
 }
 
+export function normalizeDingWorkflowProcessCode(value: unknown): string | null {
+  return clean(value)?.toUpperCase() || null
+}
+
+export function isAllowedDingWorkflowProcessCode(value: unknown): boolean {
+  const processCode = normalizeDingWorkflowProcessCode(value)
+  return Boolean(processCode && ALLOWED_PROCESS_CODE_SET.has(processCode))
+}
+
 function nonNegativeInteger(value: unknown): number {
   const number = Number(value)
   return Number.isFinite(number) && number > 0 ? Math.floor(number) : 0
@@ -216,6 +232,9 @@ async function assertDashboardAccess(session: Session | null) {
 async function fetchSourceWorkflows(pool: ConnectionPool, cursor: string | null) {
   const request = pool.request()
   request.input('cursor', mssql.NVarChar(64), cursor)
+  DING_WORKFLOW_ALLOWED_PROCESS_CODES.forEach((processCode, index) => {
+    request.input(`allowedProcessCode${index}`, mssql.NVarChar(255), processCode)
+  })
   const result = await request.query<SourceWorkflowRow>(`
     SELECT
       CONVERT(nvarchar(255), processInstanceId) AS processInstanceId,
@@ -235,10 +254,16 @@ async function fetchSourceWorkflows(pool: ConnectionPool, cursor: string | null)
       CONVERT(nvarchar(64), finishTime) AS sourceFinishedAtRaw
     FROM ${tableRef(WORKFLOW_TABLE)}
     WHERE
-      @cursor IS NULL
-      OR UPPER(LTRIM(RTRIM(COALESCE(CONVERT(nvarchar(100), status), '')))) NOT IN ('COMPLETED', 'TERMINATED', 'CANCELED')
-      OR TRY_CONVERT(datetime2, NULLIF(CONVERT(nvarchar(64), updateAt), '')) >=
-        DATEADD(minute, -5, TRY_CONVERT(datetime2, @cursor))
+      UPPER(LTRIM(RTRIM(COALESCE(CONVERT(nvarchar(255), processCode), '')))) IN (
+        @allowedProcessCode0,
+        @allowedProcessCode1
+      )
+      AND (
+        @cursor IS NULL
+        OR UPPER(LTRIM(RTRIM(COALESCE(CONVERT(nvarchar(100), status), '')))) NOT IN ('COMPLETED', 'TERMINATED', 'CANCELED')
+        OR TRY_CONVERT(datetime2, NULLIF(CONVERT(nvarchar(64), updateAt), '')) >=
+          DATEADD(minute, -5, TRY_CONVERT(datetime2, @cursor))
+      )
   `)
   return result.recordset
 }
@@ -324,7 +349,7 @@ function buildSnapshotPayload(
       originatorDeptName: clean(row.originatorDeptName),
       status: status.toUpperCase(),
       bizAction: clean(row.bizAction),
-      processCode: clean(row.processCode),
+      processCode: normalizeDingWorkflowProcessCode(row.processCode),
       flowType: clean(row.flowType),
       joinedAtRaw: clean(row.joinedAtRaw),
       sourceCreatedAtRaw: clean(row.sourceCreatedAtRaw),
@@ -427,7 +452,7 @@ export async function syncDingWorkflowSnapshots() {
   const startedAt = new Date()
   const leaseOwner = `${hostname()}:${process.pid}:${randomUUID()}`
   const state = await acquireSyncLease(leaseOwner, startedAt)
-  if (!state) return { skipped: true, rowsUpserted: 0, ongoingCount: null }
+  if (!state) return { skipped: true, rowsUpserted: 0, rowsDeleted: 0, ongoingCount: null }
 
   const pool = new mssql.ConnectionPool(buildSourceConfig())
   try {
@@ -445,7 +470,20 @@ export async function syncDingWorkflowSnapshots() {
       await upsertSnapshotBatch(rows.slice(index, index + UPSERT_BATCH_SIZE), syncedAt)
     }
 
-    const ongoingCount = await prisma.dingWorkflowSnapshot.count({ where: { isOngoing: true } })
+    const deleted = await prisma.dingWorkflowSnapshot.deleteMany({
+      where: {
+        OR: [
+          { processCode: null },
+          { processCode: { notIn: ALLOWED_PROCESS_CODE_VALUES } },
+        ],
+      },
+    })
+    const ongoingCount = await prisma.dingWorkflowSnapshot.count({
+      where: {
+        isOngoing: true,
+        processCode: { in: ALLOWED_PROCESS_CODE_VALUES },
+      },
+    })
     const sourceCursorRaw = maxSourceCursor(rows, state.sourceCursorRaw)
     await prisma.dingWorkflowSyncState.updateMany({
       where: { id: SYNC_STATE_ID, leaseOwner },
@@ -460,7 +498,7 @@ export async function syncDingWorkflowSnapshots() {
         currentOngoingCount: ongoingCount,
       },
     })
-    return { skipped: false, rowsUpserted: rows.length, ongoingCount }
+    return { skipped: false, rowsUpserted: rows.length, rowsDeleted: deleted.count, ongoingCount }
   } catch (error) {
     const message = error instanceof Error ? error.message : String(error)
     await prisma.dingWorkflowSyncState.updateMany({
@@ -487,7 +525,12 @@ function normalizeSyncStatus(state: { status: string; lastCompletedAt: Date | nu
 
 async function readSummaryWithoutAccessCheck(): Promise<OngoingDingWorkflowSummary> {
   const [total, state] = await prisma.$transaction([
-    prisma.dingWorkflowSnapshot.count({ where: { isOngoing: true } }),
+    prisma.dingWorkflowSnapshot.count({
+      where: {
+        isOngoing: true,
+        processCode: { in: ALLOWED_PROCESS_CODE_VALUES },
+      },
+    }),
     prisma.dingWorkflowSyncState.findUnique({
       where: { id: SYNC_STATE_ID },
       select: { status: true, lastCompletedAt: true },
@@ -515,6 +558,7 @@ export async function getOngoingDingWorkflowProjects(
   const query = clean(params?.query)
   const where = {
     isOngoing: true,
+    processCode: { in: ALLOWED_PROCESS_CODE_VALUES },
     ...(query ? {
       OR: [
         { title: { contains: query, mode: 'insensitive' as const } },
@@ -604,7 +648,7 @@ export function ensureHourlyDingWorkflowSyncStarted() {
           console.info('[ding-workflow-sync] 另一实例正在同步，本轮跳过')
           return
         }
-        console.info(`[ding-workflow-sync] 同步完成：更新 ${result.rowsUpserted} 条，进行中 ${result.ongoingCount} 条`)
+        console.info(`[ding-workflow-sync] 同步完成：更新 ${result.rowsUpserted} 条，清理 ${result.rowsDeleted} 条，进行中 ${result.ongoingCount} 条`)
       })
       .catch((error) => console.warn('[ding-workflow-sync] 同步失败：', error))
   }