Prior loans and lending agencies are the most important part of the bank's issuance of loans, and is also the first guarantee of whether or not it can be recovered safely after issuing loans. This is not only the process of accepting specific credit services but also the process of sorting customers. Prior loans are the most important parts of the lending decision, and this part of the implementation is very advantageous for achieving the advance of risk barriers. Before the loan investigation, it was decided whether or not to spend a lot of time and energy in the subsequent research interview to confirm whether or not to accept the credit business. The main subject of the investigation is borrowers, guarantors, mortgages and holders of their owners.