diff --git a/packages/uni-mp-weixin/dist/mp.js b/packages/uni-mp-weixin/dist/mp.js
index 393ef8c107bf380126216a9fb7ace5cad1383c93..a0536a20d6dca5780bc39e08ebcc904642a17da8 100644
--- a/packages/uni-mp-weixin/dist/mp.js
+++ b/packages/uni-mp-weixin/dist/mp.js
@@ -595,9 +595,7 @@ function validateProp (key, propsOptions, propsData, vm) {
   if (value !== undefined) {
     const propOptions = propsOptions[key];
     const type = getType(propOptions);
-    if (type === Boolean) {
-      value = !!value;
-    }
+    value = formatVal(value, type);
     const observer = propOptions && propOptions.observer;
     if (observer) {
       // 初始化时,异步触发 observer,否则 observer 中无法访问 methods 或其他
@@ -610,6 +608,15 @@ function validateProp (key, propsOptions, propsData, vm) {
   return getPropertyVal(propsOptions[key])
 }
 
+function formatVal (val, type) {
+  if (type === Boolean) {
+    return !!val
+  } else if (type === String) {
+    return String(val)
+  }
+  return val
+}
+
 function observe (observer, vm, newVal, oldVal) {
   try {
     if (typeof observer === 'function') {
@@ -665,12 +672,7 @@ function updateProperties (vm) {
   if (propsData && properties) {
     Object.keys(properties).forEach(key => {
       if (hasOwn(propsData, key)) {
-        const type = getType(properties[key]);
-        if (type === Boolean) {
-          vm[key] = !!propsData[key];
-        } else {
-          vm[key] = propsData[key];
-        }
+        vm[key] = formatVal(propsData[key], getType(properties[key]));
       }
     });
   }
diff --git a/src/core/runtime/mp/polyfill/state/properties.js b/src/core/runtime/mp/polyfill/state/properties.js
index fa2b8e71a8f9982ee31110ccc0428b732c2ed1b5..0f361c1f5504b04fd203c92ff121769a02ae4069 100644
--- a/src/core/runtime/mp/polyfill/state/properties.js
+++ b/src/core/runtime/mp/polyfill/state/properties.js
@@ -39,9 +39,7 @@ function validateProp (key, propsOptions, propsData, vm) {
   if (value !== undefined) {
     const propOptions = propsOptions[key]
     const type = getType(propOptions)
-    if (type === Boolean) {
-      value = !!value
-    }
+    value = formatVal(value, type)
     const observer = propOptions && propOptions.observer
     if (observer) {
       // 初始化时,异步触发 observer,否则 observer 中无法访问 methods 或其他
@@ -54,6 +52,15 @@ function validateProp (key, propsOptions, propsData, vm) {
   return getPropertyVal(propsOptions[key])
 }
 
+function formatVal (val, type) {
+  if (type === Boolean) {
+    return !!val
+  } else if (type === String) {
+    return String(val)
+  }
+  return val
+}
+
 function observe (observer, vm, newVal, oldVal) {
   try {
     if (typeof observer === 'function') {
@@ -109,12 +116,7 @@ export function updateProperties (vm) {
   if (propsData && properties) {
     Object.keys(properties).forEach(key => {
       if (hasOwn(propsData, key)) {
-        const type = getType(properties[key])
-        if (type === Boolean) {
-          vm[key] = !!propsData[key]
-        } else {
-          vm[key] = propsData[key]
-        }
+        vm[key] = formatVal(propsData[key], getType(properties[key]))
       }
     })
   }