In view of the continuous advancement of interest rate marketization and interest rate becoming the most important link in Internet financial supervision, this paper puts forward a model of influencing factors of interest rate of P2P lending platform, empirically studies the influencing factors of interest rate of P2P lending, and makes an indepth study of default intention of borrowers, providing a reference and theoretical basis for the development of P2P lending platform. The study finds that first, order information, borrower financial information, credit information and herding effect have an impact on borrowing interest rate; secondly, the number of defaults can reflect personal credit status, but it is not significant in exploring interest rate pricing mechanism. The number of defaults is mainly determined by repayment ability and repayment willingness. Investors should pay attention to the amount of arrears and credit inquiry records to avoid the moral hazard of borrowers. Thirdly, the number of investors has a negative impact on the interest rate of borrowing, indicating that the current number of bidders can have a positive impact on the possibility of obtaining followup bids. Investors believe that the borrower's credit is in good condition for orders with lower interest rates.