diff --git a/background.js b/background.js
index 02ef4c82..a5c43b52 100644
--- a/background.js
+++ b/background.js
@@ -10934,6 +10934,72 @@ async function reportCompletedStepSideEffectError(step, error) {
   return reportCompletedNodeSideEffectError(getNodeIdByStepForState(step, state), error);
 }
 
+function getSignupPhoneIdentityValue(state = {}) {
+  const accountIdentifierType = String(state?.accountIdentifierType || '').trim().toLowerCase();
+  return String(
+    state?.signupPhoneNumber
+    || state?.signupPhoneCompletedActivation?.phoneNumber
+    || state?.signupPhoneActivation?.phoneNumber
+    || (accountIdentifierType === 'phone' ? state?.accountIdentifier : '')
+    || ''
+  ).trim();
+}
+
+function signupPhoneIdentityValuesMatch(left = '', right = '') {
+  const leftRaw = String(left || '').trim();
+  const rightRaw = String(right || '').trim();
+  if (!leftRaw || !rightRaw) {
+    return false;
+  }
+  if (leftRaw === rightRaw) {
+    return true;
+  }
+  const leftDigits = leftRaw.replace(/\D+/g, '');
+  const rightDigits = rightRaw.replace(/\D+/g, '');
+  return Boolean(leftDigits && rightDigits && leftDigits === rightDigits);
+}
+
+async function clearSignupPhoneIdentityAfterSuccessfulFlow(completionState = {}, options = {}) {
+  const completedPhone = getSignupPhoneIdentityValue(completionState);
+  const latestState = await getState();
+  const currentPhone = getSignupPhoneIdentityValue(latestState);
+  const currentIdentifierType = String(latestState?.accountIdentifierType || '').trim().toLowerCase();
+  const hasCurrentPhoneIdentity = Boolean(
+    currentPhone
+    || latestState?.signupPhoneActivation
+    || latestState?.signupPhoneCompletedActivation
+    || currentIdentifierType === 'phone'
+  );
+
+  if (!hasCurrentPhoneIdentity) {
+    return { cleared: false, reason: 'empty' };
+  }
+
+  if (completedPhone && currentPhone && !signupPhoneIdentityValuesMatch(completedPhone, currentPhone)) {
+    return { cleared: false, reason: 'changed' };
+  }
+
+  const updates = {
+    phoneNumber: '',
+    signupPhoneNumber: '',
+    signupPhoneActivation: null,
+    signupPhoneCompletedActivation: null,
+    signupPhoneVerificationRequestedAt: null,
+    signupPhoneVerificationPurpose: '',
+  };
+  if (currentIdentifierType === 'phone') {
+    updates.accountIdentifierType = null;
+    updates.accountIdentifier = '';
+  }
+
+  await setState(updates);
+  broadcastDataUpdate(updates);
+  await addLog('手机号注册：流程成功后已清空本轮注册手机号，避免下一轮复用。', 'ok', {
+    nodeId: options?.nodeId || 'platform-verify',
+  });
+  return { cleared: true, phoneNumber: currentPhone || completedPhone };
+}
+
 async function runCompletedNodeSideEffects(nodeId, payload, completionState, lastNodeId) {
   await handleNodeData(nodeId, payload);
   if (nodeId === lastNodeId) {
@@ -10966,6 +11032,11 @@ async function completeNodeFromBackground(nodeId, payload = {}) {
   await addLog('已完成', 'ok', { nodeId: normalizedNodeId });
 
   if (normalizedNodeId === lastNodeId) {
+    if (typeof clearSignupPhoneIdentityAfterSuccessfulFlow === 'function') {
+      await clearSignupPhoneIdentityAfterSuccessfulFlow(latestState, {
+        nodeId: normalizedNodeId,
+      });
+    }
     notifyNodeComplete(normalizedNodeId, payload);
     void runCompletedNodeSideEffects(normalizedNodeId, payload, completionState, lastNodeId)
       .catch((error) => reportCompletedNodeSideEffectError(normalizedNodeId, error));
diff --git a/tests/background-step-completion.test.js b/tests/background-step-completion.test.js
index 7c7d38a6..e4169b14 100644
--- a/tests/background-step-completion.test.js
+++ b/tests/background-step-completion.test.js
@@ -51,17 +51,18 @@ function extractFunction(name) {
   return source.slice(start, end);
 }
 
-function createApi(events, lastNodeId = 'platform-verify') {
-  return new Function('events', 'lastNodeId', `
+function createApi(events, lastNodeId = 'platform-verify', initialState = {}) {
+  return new Function('events', 'lastNodeId', 'initialState', `
 let stopRequested = false;
 const LOG_PREFIX = '[test]';
+let currentState = { nodeStatuses: {}, accountContributionEnabled: true, ...initialState };
 const STOP_ERROR_MESSAGE = '流程已被用户停止。';
 function getErrorMessage(error) {
   return error?.message || String(error || '');
 }
 async function getState() {
   events.push({ type: 'getState' });
-  return { nodeStatuses: {}, accountContributionEnabled: true };
+  return currentState;
 }
 function getLastNodeIdForState() {
   return lastNodeId;
@@ -69,6 +70,13 @@ function getLastNodeIdForState() {
 async function setNodeStatus(nodeId, status) {
   events.push({ type: 'status', nodeId, status });
 }
+async function setState(updates) {
+  currentState = { ...currentState, ...updates };
+  events.push({ type: 'setState', updates });
+}
+function broadcastDataUpdate(updates) {
+  events.push({ type: 'broadcast', updates });
+}
 async function addLog(message, level, options = {}) {
   events.push({ type: 'log', message, level, options });
 }
@@ -89,11 +97,14 @@ async function handleNodeData(nodeId, payload) {
 async function appendAndBroadcastAccountRunRecord(status, state) {
   events.push({ type: 'record', status, state });
 }
+${extractFunction('getSignupPhoneIdentityValue')}
+${extractFunction('signupPhoneIdentityValuesMatch')}
+${extractFunction('clearSignupPhoneIdentityAfterSuccessfulFlow')}
 ${extractFunction('runCompletedNodeSideEffects')}
 ${extractFunction('reportCompletedNodeSideEffectError')}
 ${extractFunction('completeNodeFromBackground')}
-return { completeNodeFromBackground };
-`)(events, lastNodeId);
+return { completeNodeFromBackground, getCurrentState: () => currentState };
+`)(events, lastNodeId, initialState);
 }
 
 test('completeNodeFromBackground releases final node before slow post-completion side effects', async () => {
@@ -124,3 +135,27 @@ test('completeNodeFromBackground keeps non-final node data handling before compl
   assert.equal(types.indexOf('handle-done') < types.indexOf('notify'), true);
   assert.equal(types.includes('record'), false);
 });
+
+test('completeNodeFromBackground clears signup phone identity before releasing final node', async () => {
+  const events = [];
+  const api = createApi(events, 'platform-verify', {
+    accountIdentifierType: 'phone',
+    accountIdentifier: '+56979206303',
+    signupPhoneNumber: '+56979206303',
+    signupPhoneActivation: { activationId: 'active', phoneNumber: '+56979206303' },
+    signupPhoneCompletedActivation: { activationId: 'done', phoneNumber: '+56979206303' },
+    signupPhoneVerificationRequestedAt: 123,
+    signupPhoneVerificationPurpose: 'login',
+  });
+
+  await api.completeNodeFromBackground('platform-verify', { localhostUrl: 'http://localhost:1455/auth/callback?code=ok' });
+
+  const types = events.map((event) => event.type);
+  assert.equal(types.indexOf('setState') < types.indexOf('notify'), true);
+  assert.equal(types.indexOf('broadcast') < types.indexOf('notify'), true);
+  assert.equal(api.getCurrentState().signupPhoneNumber, '');
+  assert.equal(api.getCurrentState().signupPhoneActivation, null);
+  assert.equal(api.getCurrentState().signupPhoneCompletedActivation, null);
+  assert.equal(api.getCurrentState().accountIdentifierType, null);
+  assert.equal(api.getCurrentState().accountIdentifier, '');
+});