The China Construction Bank credit card may be frozen due to the following reasons:

1. Overdue repayment: If you fail to pay the minimum payment amount on the credit card bill or repay in full If you repay within the due date, the bank may freeze your credit card account.

2. Exceeding the credit limit: If your credit card consumption has exceeded the credit limit, the bank may suspend the use of your credit card.

3. Suspected fraud: If the bank suspects that you have committed fraud, such as fraudulent use, false transactions, etc., it will take measures to freeze the credit card account.

4. Security risk: The bank may detect abnormal transactions on your credit card, such as being stolen. In order to protect the security of your account, the bank will freeze the credit card.

If your credit card is frozen, you can take the following steps:

1. Contact China Construction Bank customer service: Call China Construction Bank customer service number to ask about the specific reason for the freeze and obtain further unfreezing steps. and requirements.

2. Provide information and unfreeze application: Provide relevant identity certificates and information as required by the bank, and submit an unfreezing application.

3. Waiting for processing: The bank will review your application, and the processing time will depend on the specific circumstances.

It is recommended that you contact China Construction Bank customer service to understand the specific reasons why your account has been frozen, and apply and operate for unfreezing in accordance with the bank's requirements.