diff --git a/packages/style-unit/CHANGELOG.md b/packages/style-unit/CHANGELOG.md
index 272478e286..9f6d7ce3ab 100644
--- a/packages/style-unit/CHANGELOG.md
+++ b/packages/style-unit/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Changelog
 
+## v3.0.6
+
+- Fix: maximum call caused by large base64.
+
 ## v3.0.5
 
 - Fix: fix transform rpx error in node env.
diff --git a/packages/style-unit/package.json b/packages/style-unit/package.json
index 6ed0ec020e..66bc86aad6 100644
--- a/packages/style-unit/package.json
+++ b/packages/style-unit/package.json
@@ -1,6 +1,6 @@
 {
   "name": "style-unit",
-  "version": "3.0.5",
+  "version": "3.0.6",
   "description": "style-unit",
   "license": "BSD-3-Clause",
   "main": "lib/index.js",
diff --git a/packages/style-unit/src/__tests__/style-unit.web.js b/packages/style-unit/src/__tests__/style-unit.web.js
index ba390ad67c..1c6822bf83 100644
--- a/packages/style-unit/src/__tests__/style-unit.web.js
+++ b/packages/style-unit/src/__tests__/style-unit.web.js
@@ -48,6 +48,11 @@ describe('Web style-unit', () => {
       expect(convertUnit('375rpx 20px 375rpx', 'margin')).toEqual('100vw 20px 100vw');
       expect(convertUnit('translateX(375rpx) translateY(375rpx)', 'transform')).toEqual('translateX(100vw) translateY(100vw)');
     });
+
+    it('should not convert base64', () => {
+      const base64String = 'url(\'data:image/png;base64,iVBORw30rpx...)';
+      expect(convertUnit(base64String, 'backgroundImage')).toEqual(base64String);
+    });
   });
 
   describe('exported API', () => {
diff --git a/packages/style-unit/src/index.js b/packages/style-unit/src/index.js
index 9facedb339..8109174784 100644
--- a/packages/style-unit/src/index.js
+++ b/packages/style-unit/src/index.js
@@ -127,6 +127,19 @@ export function setTargetPlatform(platform) {
   targetPlatform = platform;
 }
 
+const _convertUnit = cached((value, prop, platform) => {
+  if (platform) {
+    setTargetPlatform(platform);
+  }
+  return isRpx(value) ? calcRpx(value) : value;
+});
+
+const REG_BASE64 = /data:image\/(png|jpg|jpeg|gif|svg|webp|bmp|dpg);base64,/;
+function isBase64(str) {
+  // Maximal base64 string start with `url('data:image/jpeg;base64,` which contains 30 characters.
+  return typeof str === 'string' && REG_BASE64.test(str.substring(0, 30));
+}
+
 /**
  * Convert rpx.
  * @param value
@@ -134,9 +147,7 @@ export function setTargetPlatform(platform) {
  * @param platform
  * @return {String} Transformed value.
  */
-export const convertUnit = cached((value, prop, platform) => {
-  if (platform) {
-    setTargetPlatform(platform);
-  }
-  return isRpx(value) ? calcRpx(value) : value;
-});
+export const convertUnit = (value, prop, platform) => {
+  // Do not to convert base64 value which may cause maximum error.
+  return isBase64(value) ? value : _convertUnit(value, prop, platform);
+};