1. Transaction restriction: In the locked state, the credit card cannot conduct any transaction, including online shopping, offline payment and cash withdrawal, which means that the cardholder cannot use the credit card for any consumption or payment.

2. Security protection: Setting the credit card lock status can help protect the security of the cardholder's account and prevent unauthorized transactions or fraud. This is an extra layer of security to ensure that credit cards can only be controlled and used by cardholders.