The Civil Code stipulates how to investigate the responsibility of the guarantor after paying back the money.

First of all, negotiate with the debtor and give the other party a certain repayment period. If it is overdue, it can be recovered through litigation. 1. 1. Write a complaint, which shall include the following items: (1) The name, gender, age, nationality, occupation, work unit, domicile and contact information of the plaintiff, the name and domicile of the legal person or other organization, and the name, position and contact information of the legal representative or principal responsible person; (2) Information such as the name, gender, work unit and domicile of the defendant, and information such as the name and domicile of the legal person or other organization; (3) the request and the facts and reasons on which it is based; (4) Evidence and its sources, names and residences of witnesses. Secondly, collect the evidence prepared for you. Third, finally, bring the complaint and relevant evidence to the court with jurisdiction and pay the corresponding fees.