Credit risk refers to the possibility that the trading object is unwilling or loses the ability to fulfill the contractual obligations for various reasons, and causes losses to commercial banks. In credit activities, if the borrower fails to repay the principal and interest of the loan on time and the guarantor fails to fulfill the guarantee obligation, there is a credit risk. But this is not exactly the same as default, will only reduce the credit rating of enterprises, which greatly increases the possibility of customer default.