diff --git a/lib/extend/injector.js b/lib/extend/injector.js
index 5c468f4176..34effb37d2 100644
--- a/lib/extend/injector.js
+++ b/lib/extend/injector.js
@@ -18,7 +18,7 @@ class Injector {
     return Array.from(this.store[entry]);
   }
 
-  register(entry, value, to = '') {
+  register(entry, value, to = 'default') {
     if (!entry) throw new TypeError('entry is required');
     if (typeof value === 'function') value = value();
 
diff --git a/lib/plugins/filter/after_render/injector.js b/lib/plugins/filter/after_render/injector.js
index 477f344dad..b772ad0d34 100644
--- a/lib/plugins/filter/after_render/injector.js
+++ b/lib/plugins/filter/after_render/injector.js
@@ -1,53 +1,38 @@
 'use strict';
 
+const { Cache } = require('hexo-util');
+const cache = new Cache();
+
 function injectFilter(data, locals = { page: {} }) {
   const { injector: _Injector } = this.extend;
 
-  const is = input => {
-    let result = true;
+  const current = () => {
     const { page } = locals;
 
-    switch (input) {
-      case 'home':
-        result = Boolean(page.__index);
-        break;
-
-      case 'post':
-        result = Boolean(page.__post);
-        break;
-
-      case 'page':
-        result = Boolean(page.__page);
-        break;
-
-      case 'archive':
-        result = Boolean(page.archive);
-        break;
-
-      case 'category':
-        result = Boolean(page.category);
-        break;
-
-      case 'tag':
-        result = Boolean(page.tag);
-        break;
-
-      default:
-        result = true;
-    }
-
-    return result;
+    if (page.__index) return 'home';
+    if (page.__post) return 'post';
+    if (page.__page) return 'page';
+    if (page.archive) return 'archive';
+    if (page.category) return 'category';
+    if (page.tag) return 'tag';
+    return 'default';
   };
 
   function injector(data, pattern, flag, isBegin = true) {
     if (data.includes(`hexo injector ${flag}`)) return data;
 
-    const arr = _Injector.get(flag).filter(i => is(i.to)).map(i => i.value);
+    const arr = cache.apply(
+      `${flag}-${current()}-arr`,
+      _Injector.get(flag).filter(i => i.to === current()).map(i => i.value)
+    );
 
     if (!arr.length) return data;
 
     return data.replace(pattern, str => {
-      const code = arr.reduce((a, c) => a + c, '');
+      const code = cache.apply(
+        `${flag}-${current()}-code`,
+        arr.reduce((a, c) => a + c, '')
+      );
 
       if (isBegin) {
         return str