diff --git a/scripts/backend/build-backend.mjs b/scripts/backend/build-backend.mjs
index c42fe5a3..d7776c29 100644
--- a/scripts/backend/build-backend.mjs
+++ b/scripts/backend/build-backend.mjs
@@ -5,6 +5,8 @@ import { fileURLToPath } from 'node:url';
 
 import {
   copyTree,
+  createPythonInstallEnv,
+  prunePythonBytecodeArtifacts,
   resolveAndValidateRuntimeSource,
   resolveRuntimePython,
 } from './runtime-layout-utils.mjs';
@@ -466,11 +468,13 @@ const installRuntimeDependencies = (runtimePython) => {
       'pip',
       '--disable-pip-version-check',
       'install',
+      '--no-compile',
       ...pipArgs,
     ];
     return spawnSync(runtimePython.absolute, installArgs, {
       cwd: outputDir,
       stdio: 'inherit',
+      env: createPythonInstallEnv(),
       windowsHide: true,
     });
   };
@@ -562,6 +566,20 @@ const installRuntimeDependencies = (runtimePython) => {
       );
     }
   }
+
+  const bytecodeCleanupStats = prunePythonBytecodeArtifacts(runtimeDir);
+  if (
+    bytecodeCleanupStats.removedCacheDirs > 0 ||
+    bytecodeCleanupStats.removedBytecodeFiles > 0 ||
+    bytecodeCleanupStats.removedOrphanBytecodeFiles > 0
+  ) {
+    console.log(
+      '[build-backend] removed Python bytecode artifacts ' +
+        `(${bytecodeCleanupStats.removedCacheDirs} cache dirs, ` +
+        `${bytecodeCleanupStats.removedBytecodeFiles} cached files, ` +
+        `${bytecodeCleanupStats.removedOrphanBytecodeFiles} orphan files).`,
+    );
+  }
 };
 
 const main = () => {
diff --git a/scripts/backend/runtime-layout-utils.mjs b/scripts/backend/runtime-layout-utils.mjs
index e598003d..0c4c7be0 100644
--- a/scripts/backend/runtime-layout-utils.mjs
+++ b/scripts/backend/runtime-layout-utils.mjs
@@ -1,6 +1,8 @@
 import fs from 'node:fs';
 import path from 'node:path';
 
+const isBytecodeFile = (entryName) => entryName.endsWith('.pyc') || entryName.endsWith('.pyo');
+
 const shouldCopy = (sourcePath) => {
   const base = path.basename(sourcePath);
   if (base === '__pycache__' || base === '.pytest_cache' || base === '.ruff_cache') {
@@ -9,7 +11,7 @@ const shouldCopy = (sourcePath) => {
   if (base === '.git' || base === '.mypy_cache' || base === '.DS_Store') {
     return false;
   }
-  if (base.endsWith('.pyc') || base.endsWith('.pyo')) {
+  if (isBytecodeFile(base)) {
     return false;
   }
   return true;
@@ -24,6 +26,59 @@ export const copyTree = (fromPath, toPath, { dereference = false } = {}) => {
   });
 };
 
+export const createPythonInstallEnv = (env = process.env) => ({
+  ...env,
+  PYTHONDONTWRITEBYTECODE: '1',
+});
+
+export const prunePythonBytecodeArtifacts = (rootDir) => {
+  const stats = {
+    removedCacheDirs: 0,
+    removedBytecodeFiles: 0,
+    removedOrphanBytecodeFiles: 0,
+  };
+
+  const visit = (directoryPath, { inPycache = false } = {}) => {
+    for (const entry of fs.readdirSync(directoryPath, { withFileTypes: true })) {
+      const entryPath = path.join(directoryPath, entry.name);
+
+      if (entry.isDirectory()) {
+        const childInPycache = inPycache || entry.name === '__pycache__';
+
+        if (entry.name === '__pycache__' && !inPycache) {
+          stats.removedCacheDirs += 1;
+        }
+
+        visit(entryPath, { inPycache: childInPycache });
+
+        if (childInPycache) {
+          fs.rmdirSync(entryPath);
+        }
+
+        continue;
+      }
+
+      if (inPycache) {
+        stats.removedBytecodeFiles += 1;
+        fs.rmSync(entryPath, { force: true });
+        continue;
+      }
+
+      if (isBytecodeFile(entry.name)) {
+        stats.removedOrphanBytecodeFiles += 1;
+        fs.rmSync(entryPath, { force: true });
+      }
+    }
+  };
+
+  if (!fs.existsSync(rootDir)) {
+    return stats;
+  }
+
+  visit(rootDir);
+  return stats;
+};
+
 export const resolveAndValidateRuntimeSource = ({ projectRoot, outputDir, runtimeSource }) => {
   if (!runtimeSource) {
     throw new Error(
diff --git a/scripts/backend/runtime-layout-utils.test.mjs b/scripts/backend/runtime-layout-utils.test.mjs
new file mode 100644
index 00000000..c82d4be9
--- /dev/null
+++ b/scripts/backend/runtime-layout-utils.test.mjs
@@ -0,0 +1,54 @@
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import assert from 'node:assert/strict';
+import { test } from 'node:test';
+
+import * as runtimeLayoutUtils from './runtime-layout-utils.mjs';
+
+test('createPythonInstallEnv forces PYTHONDONTWRITEBYTECODE while preserving other env vars', () => {
+  assert.equal(typeof runtimeLayoutUtils.createPythonInstallEnv, 'function');
+
+  const env = runtimeLayoutUtils.createPythonInstallEnv({
+    PATH: '/tmp/bin',
+    PYTHONDONTWRITEBYTECODE: '0',
+  });
+
+  assert.equal(env.PATH, '/tmp/bin');
+  assert.equal(env.PYTHONDONTWRITEBYTECODE, '1');
+});
+
+test('prunePythonBytecodeArtifacts removes bytecode files and cache directories recursively', () => {
+  assert.equal(typeof runtimeLayoutUtils.prunePythonBytecodeArtifacts, 'function');
+
+  const fixtureRoot = fs.mkdtempSync(path.join(os.tmpdir(), 'astrbot-bytecode-fixture-'));
+  const nestedPackageDir = path.join(fixtureRoot, 'python', 'lib', 'python3.12', 'site-packages', 'demo');
+  const cacheDir = path.join(nestedPackageDir, '__pycache__');
+  const nestedCacheDir = path.join(cacheDir, 'nested');
+  const sourceFile = path.join(nestedPackageDir, 'module.py');
+  const bytecodeFile = path.join(cacheDir, 'module.cpython-312.pyc');
+  const nestedCacheFile = path.join(nestedCacheDir, 'metadata.txt');
+  const orphanBytecodeFile = path.join(fixtureRoot, 'python', 'bin', 'tool.pyc');
+
+  fs.mkdirSync(nestedCacheDir, { recursive: true });
+  fs.mkdirSync(path.dirname(orphanBytecodeFile), { recursive: true });
+  fs.writeFileSync(sourceFile, 'value = 1\n', 'utf8');
+  fs.writeFileSync(bytecodeFile, 'bytecode', 'utf8');
+  fs.writeFileSync(nestedCacheFile, 'metadata', 'utf8');
+  fs.writeFileSync(orphanBytecodeFile, 'bytecode', 'utf8');
+
+  const stats = runtimeLayoutUtils.prunePythonBytecodeArtifacts(fixtureRoot);
+
+  assert.deepEqual(stats, {
+    removedCacheDirs: 1,
+    removedBytecodeFiles: 2,
+    removedOrphanBytecodeFiles: 1,
+  });
+  assert.equal(fs.existsSync(cacheDir), false);
+  assert.equal(fs.existsSync(bytecodeFile), false);
+  assert.equal(fs.existsSync(nestedCacheFile), false);
+  assert.equal(fs.existsSync(orphanBytecodeFile), false);
+  assert.equal(fs.existsSync(sourceFile), true);
+
+  fs.rmSync(fixtureRoot, { recursive: true, force: true });
+});