1. Credit card maintenance refers to a financial management method that uses the preferential policies of credit cards to reasonably allocate consumption and obtain income. The basic principles of credit card maintenance are: rationally allocate consumption, control liabilities, rationally utilize credit card preferential policies, and obtain benefits.

2. First, we need to reasonably allocate consumption and control liabilities. The basic principles of credit card maintenance are: consumption should be reasonable, do not exceed your ability to pay, control debt, and do not allow debt to accumulate too much.

3. Secondly, make reasonable use of credit card preferential policies to obtain benefits. Credit card companies will launch various preferential policies from time to time, such as points, cash back, discounts, etc. You can take advantage of these preferential policies to earn profits.

4. Again, pay attention to the safety of credit card use. The safety of credit card use is the basis of credit card maintenance. You should pay attention to protecting your credit card information and do not leak it at will to avoid adverse events such as credit card fraud.

5. Finally, check your credit card bills regularly and pay them on time. The basic principle of maintaining a credit card is: check your credit card bills regularly and pay your bills in a timely manner to avoid adverse events such as overdue payments.