diff --git a/.changeset/fix-privkey-prefix.md b/.changeset/fix-privkey-prefix.md
new file mode 100644
index 0000000..a420ec6
--- /dev/null
+++ b/.changeset/fix-privkey-prefix.md
@@ -0,0 +1,5 @@
+---
+"@offckb/cli": patch
+---
+
+fix(cli): standardize private key inputs and fix 0x prefix parsing error (#422)
diff --git a/src/sdk/ckb.ts b/src/sdk/ckb.ts
index 5276de7..1c07cdc 100644
--- a/src/sdk/ckb.ts
+++ b/src/sdk/ckb.ts
@@ -2,7 +2,7 @@
 // to replace lumos with ccc
 
 import { ccc, ClientPublicMainnet, ClientPublicTestnet, OutPointLike, Script } from '@ckb-ccc/core';
-import { isValidNetworkString } from '../util/validator';
+import { isValidNetworkString, normalizePrivKey } from '../util/validator';
 import { networks } from './network';
 import { buildCCCDevnetKnownScripts } from '../scripts/private';
 import { Migration } from '../deploy/migration';
@@ -81,7 +81,8 @@ export class CKB {
   }
 
   buildSigner(privateKey: HexString) {
-    const signer = new ccc.SignerCkbPrivateKey(this.client, privateKey);
+    const normalizedKey = normalizePrivKey(privateKey);
+    const signer = new ccc.SignerCkbPrivateKey(this.client, normalizedKey);
     return signer;
   }
 
diff --git a/src/util/validator.ts b/src/util/validator.ts
index 5566e52..53e9fe7 100644
--- a/src/util/validator.ts
+++ b/src/util/validator.ts
@@ -73,3 +73,43 @@ export function isValidVersion(version: unknown): boolean {
   // Test the version against the regex
   return versionRegex.test(version);
 }
+
+export function normalizePrivKey(privKey: string): string {
+  // Trim surrounding whitespaces
+  let key = privKey ? privKey.trim() : '';
+
+  if (!key) {
+    throw new Error('Private key is required.');
+  }
+
+  // Strip surrounding quotes
+  if (key.startsWith('"') && key.endsWith('"')) {
+    key = key.slice(1, -1);
+  }
+  if (key.startsWith("'") && key.endsWith("'")) {
+    key = key.slice(1, -1);
+  }
+
+  // Trim again to normalize whitespace that was inside surrounding quotes
+  key = key.trim();
+
+  // Remove standard 0x/0X prefix if it exists manually for normalization
+  if (/^0x/i.test(key)) {
+    key = key.slice(2);
+  }
+
+  // Validate only hex characters are left
+  if (!/^[0-9a-fA-F]+$/.test(key)) {
+    throw new Error('Invalid private key: contains non-hexadecimal characters.');
+  }
+
+  // Enforce exactly 32 bytes length
+  if (key.length !== 64) {
+    throw new Error(
+      `Invalid private key length: expected 32 bytes (64 hex characters), but got ${key.length} characters (excluding 0x prefix).`,
+    );
+  }
+
+  // Return the formally strictly padded ckb format `0x` string
+  return '0x' + key;
+}
diff --git a/tests/validator.test.ts b/tests/validator.test.ts
new file mode 100644
index 0000000..9b57b26
--- /dev/null
+++ b/tests/validator.test.ts
@@ -0,0 +1,46 @@
+import { normalizePrivKey } from '../src/util/validator';
+
+describe('normalizePrivKey', () => {
+  const validHex64 = '1234567812345678123456781234567812345678123456781234567812345678';
+
+  it('should throw an error for empty or formatting values', () => {
+    expect(() => normalizePrivKey('')).toThrow('Private key is required.');
+    expect(() => normalizePrivKey('   ')).toThrow('Private key is required.');
+  });
+
+  it('should accept a 64-character hex string without 0x prefix', () => {
+    const key = validHex64;
+    expect(normalizePrivKey(key)).toBe('0x' + key);
+  });
+
+  it('should accept a 64-character hex string with 0x prefix', () => {
+    const key = '0x' + validHex64;
+    expect(normalizePrivKey(key)).toBe('0x' + validHex64);
+  });
+
+  it('should accept a 64-character hex string with 0X prefix (case-insensitive)', () => {
+    const key = '0X' + validHex64;
+    expect(normalizePrivKey(key)).toBe('0x' + validHex64);
+  });
+
+  it('should correctly trim spaces inside quotes', () => {
+    const key = `'  0x${validHex64}  '`;
+    expect(normalizePrivKey(key)).toBe('0x' + validHex64);
+
+    const key2 = `" 0X${validHex64} "`;
+    expect(normalizePrivKey(key2)).toBe('0x' + validHex64);
+  });
+
+  it('should throw an error if the key contains non-hexadecimal characters', () => {
+    const invalidHex = validHex64.slice(0, -1) + 'G'; // Replace last char with 'G' (invalid hex)
+    expect(() => normalizePrivKey(invalidHex)).toThrow('Invalid private key: contains non-hexadecimal characters.');
+  });
+
+  it('should throw an error if the key length is incorrect', () => {
+    const shortKey = validHex64.slice(0, 62);
+    expect(() => normalizePrivKey(shortKey)).toThrow('Invalid private key length');
+
+    const longKey = validHex64 + '12';
+    expect(() => normalizePrivKey(longKey)).toThrow('Invalid private key length');
+  });
+});