diff --git a/.changeset/devnet-config-hint-fix.md b/.changeset/devnet-config-hint-fix.md
new file mode 100644
index 0000000..85cbfca
--- /dev/null
+++ b/.changeset/devnet-config-hint-fix.md
@@ -0,0 +1,16 @@
+---
+'@offckb/cli': patch
+---
+
+fix(devnet): only show init hint for InitializationError
+
+The `offckb devnet config` command was showing the "run `offckb node` once to initialize devnet config files first" hint for ALL errors, including user input errors like invalid `--set` syntax or validation failures.
+
+Now the hint is only shown for actual initialization errors (missing config path, ckb.toml, or miner.toml), making error messages clearer and less misleading.
+
+- Added `InitializationError` class to distinguish initialization errors from user input errors
+- Updated `createDevnetConfigEditor()` to throw `InitializationError` for missing files/paths
+- Modified `devnetConfig()` catch block to only show hint for `InitializationError`
+- Added type safety guard for error handling
+
+Fixes #406
diff --git a/src/cmd/devnet-config.ts b/src/cmd/devnet-config.ts
index cc8b5d3..8ccfbfe 100644
--- a/src/cmd/devnet-config.ts
+++ b/src/cmd/devnet-config.ts
@@ -1,6 +1,6 @@
 import { readSettings } from '../cfg/setting';
 import { logger } from '../util/logger';
-import { createDevnetConfigEditor } from '../devnet/config-editor';
+import { createDevnetConfigEditor, InitializationError } from '../devnet/config-editor';
 import { runDevnetConfigTui } from '../tui/devnet-config-tui';
 
 export interface DevnetConfigOptions {
@@ -72,8 +72,13 @@ export async function devnetConfig(options: DevnetConfigOptions = {}) {
 
     logger.info('No changes saved.');
   } catch (error) {
-    logger.error((error as Error).message);
-    logger.info('Tip: run `offckb node` once to initialize devnet config files first.');
+    const message = error instanceof Error ? error.message : String(error);
+    logger.error(message);
+
+    if (error instanceof InitializationError) {
+      logger.info('Tip: run `offckb node` once to initialize devnet config files first.');
+    }
+
     process.exitCode = 1;
   }
 }
diff --git a/src/devnet/config-editor.ts b/src/devnet/config-editor.ts
index 5c280dc..d4ef20e 100644
--- a/src/devnet/config-editor.ts
+++ b/src/devnet/config-editor.ts
@@ -679,13 +679,13 @@ export function createDevnetConfigEditor(configPath: string): DevnetConfigEditor
   const minerTomlPath = path.join(configPath, 'ckb-miner.toml');
 
   if (!fs.existsSync(configPath)) {
-    throw new Error(`Devnet config path does not exist: ${configPath}`);
+    throw new InitializationError(`Devnet config path does not exist: ${configPath}`);
   }
   if (!fs.existsSync(ckbTomlPath)) {
-    throw new Error(`Missing file: ${ckbTomlPath}`);
+    throw new InitializationError(`Missing file: ${ckbTomlPath}`);
   }
   if (!fs.existsSync(minerTomlPath)) {
-    throw new Error(`Missing file: ${minerTomlPath}`);
+    throw new InitializationError(`Missing file: ${minerTomlPath}`);
   }
 
   const ckbConfig = readTomlFile(ckbTomlPath);
@@ -693,3 +693,10 @@ export function createDevnetConfigEditor(configPath: string): DevnetConfigEditor
 
   return new DevnetConfigEditor(configPath, ckbConfig, minerConfig);
 }
+
+export class InitializationError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = 'InitializationError';
+  }
+}
diff --git a/tests/devnet-config-command.test.ts b/tests/devnet-config-command.test.ts
index c976e9a..507b764 100644
--- a/tests/devnet-config-command.test.ts
+++ b/tests/devnet-config-command.test.ts
@@ -13,6 +13,12 @@ jest.mock('../src/cfg/setting', () => ({
 
 jest.mock('../src/devnet/config-editor', () => ({
   createDevnetConfigEditor: jest.fn(),
+  InitializationError: class InitializationError extends Error {
+    constructor(message: string) {
+      super(message);
+      this.name = 'InitializationError';
+    }
+  },
 }));
 
 jest.mock('../src/tui/devnet-config-tui', () => ({
@@ -78,3 +84,95 @@ describe('devnet config command fallback behavior', () => {
     expect(process.exitCode).toBe(1);
   });
 });
+
+describe('error handling with init hint', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+    process.exitCode = undefined;
+    (createDevnetConfigEditor as jest.Mock).mockReturnValue({
+      setFieldValue: jest.fn(),
+      save: jest.fn(),
+    });
+  });
+
+  afterEach(() => {
+    process.exitCode = undefined;
+  });
+
+  it('should NOT show init hint for parse errors (--set invalid)', async () => {
+    await devnetConfig({ set: ['invalid'] });
+
+    expect(logger.error).toHaveBeenCalledWith(expect.stringContaining('Invalid --set item'));
+    expect(logger.info).not.toHaveBeenCalledWith(
+      'Tip: run `offckb node` once to initialize devnet config files first.',
+    );
+    expect(process.exitCode).toBe(1);
+  });
+
+  it('should NOT show init hint for unknown field errors', async () => {
+    (createDevnetConfigEditor as jest.Mock).mockImplementation(() => {
+      throw new Error("Unknown field 'unknown.field'.");
+    });
+
+    await devnetConfig({ set: ['unknown.field=value'] });
+
+    expect(logger.error).toHaveBeenCalledWith(expect.stringContaining('Unknown field'));
+    expect(logger.info).not.toHaveBeenCalledWith(
+      'Tip: run `offckb node` once to initialize devnet config files first.',
+    );
+    expect(process.exitCode).toBe(1);
+  });
+
+  it('should NOT show init hint for validation errors', async () => {
+    (createDevnetConfigEditor as jest.Mock).mockImplementation(() => {
+      throw new Error('Value must be a positive integer.');
+    });
+
+    await devnetConfig({ set: ['miner.client.poll_interval=0'] });
+
+    expect(logger.error).toHaveBeenCalledWith(expect.stringContaining('Value must be a positive integer'));
+    expect(logger.info).not.toHaveBeenCalledWith(
+      'Tip: run `offckb node` once to initialize devnet config files first.',
+    );
+    expect(process.exitCode).toBe(1);
+  });
+
+  it('should show init hint for missing config path (InitializationError)', async () => {
+    const { InitializationError } = require('../src/devnet/config-editor');
+    (createDevnetConfigEditor as jest.Mock).mockImplementation(() => {
+      throw new InitializationError('Devnet config path does not exist: /missing/path');
+    });
+
+    await devnetConfig({ set: ['ckb.logger.filter=info'] });
+
+    expect(logger.error).toHaveBeenCalledWith(expect.stringContaining('Devnet config path does not exist'));
+    expect(logger.info).toHaveBeenCalledWith('Tip: run `offckb node` once to initialize devnet config files first.');
+    expect(process.exitCode).toBe(1);
+  });
+
+  it('should show init hint for missing ckb.toml (InitializationError)', async () => {
+    const { InitializationError } = require('../src/devnet/config-editor');
+    (createDevnetConfigEditor as jest.Mock).mockImplementation(() => {
+      throw new InitializationError('Missing file: /path/ckb.toml');
+    });
+
+    await devnetConfig({ set: ['ckb.logger.filter=info'] });
+
+    expect(logger.error).toHaveBeenCalledWith(expect.stringContaining('Missing file'));
+    expect(logger.info).toHaveBeenCalledWith('Tip: run `offckb node` once to initialize devnet config files first.');
+    expect(process.exitCode).toBe(1);
+  });
+
+  it('should show init hint for missing miner.toml (InitializationError)', async () => {
+    const { InitializationError } = require('../src/devnet/config-editor');
+    (createDevnetConfigEditor as jest.Mock).mockImplementation(() => {
+      throw new InitializationError('Missing file: /path/ckb-miner.toml');
+    });
+
+    await devnetConfig({ set: ['ckb.logger.filter=info'] });
+
+    expect(logger.error).toHaveBeenCalledWith(expect.stringContaining('Missing file'));
+    expect(logger.info).toHaveBeenCalledWith('Tip: run `offckb node` once to initialize devnet config files first.');
+    expect(process.exitCode).toBe(1);
+  });
+});