diff --git a/lib/routes/bilibili/manga-update.ts b/lib/routes/bilibili/manga-update.ts
index 672f816ab933c3b..92102a2070a85e7 100644
--- a/lib/routes/bilibili/manga-update.ts
+++ b/lib/routes/bilibili/manga-update.ts
@@ -1,4 +1,5 @@
 import { Route } from '@/types';
+import cache from '@/utils/cache';
 import got from '@/utils/got';
 import { Go } from './wasm-exec.js';
 
@@ -27,12 +28,18 @@ export const route: Route = {
 
 // Based on https://github.com/SocialSisterYi/bilibili-API-collect/issues/1168#issuecomment-2620749895
 async function genReqSign(query, body) {
-    const wasm_resp = await got('https://s1.hdslb.com/bfs/manga-static/manga-pc/6732b1bf426cfc634293.wasm', {
-        responseType: 'arrayBuffer',
+    // Cache the wasm binary as it's quite large (~2MB)
+    // Here the binary is saved as base64 as the cache stores strings
+    const wasm_buffer_base64 = await cache.tryGet('bilibili-manga-wasm-20250208', async () => {
+        const wasm_resp = await got('https://s1.hdslb.com/bfs/manga-static/manga-pc/6732b1bf426cfc634293.wasm', {
+            responseType: 'arrayBuffer',
+        });
+        return Buffer.from(wasm_resp.data).toString('base64');
     });
+    const wasm_buffer = Buffer.from(wasm_buffer_base64, 'base64');
 
     const go = new Go();
-    const { instance } = await WebAssembly.instantiate(wasm_resp.data, go.importObject);
+    const { instance } = await WebAssembly.instantiate(wasm_buffer, go.importObject);
     go.run(instance);
     if (void 0 === globalThis.genReqSign) {
         throw new Error('WASM function not available');