The method to check the card number in Bank of China Mobile Banking is as follows:

1. Enter Bank of China Mobile Banking, find "My" in the lower right corner, and click to enter.

2. After entering My Account, find the "My Account" item and click to enter.

3. After entering my account, find the bank card you want to check the card number and click to enter.

4. After entering the bank card, find the "Show complete account number" item in the upper right corner and click to enter.

5. At this time, you can see all the card numbers of the card. If necessary, you can copy the card and save it.