This paper analyzes the optimal interest rate and screening strategy of online lending platform. The main characteristics of fee setting and project screening of online lending platform is first presented. Then, we establish and solve a model on online lending interest rate and project screening. At last, the effect of some factors, such as fee rate, on optimal strategy and expected profit of online lending platform is explored through numerical analysis. Results indicate the following: Firstly, there is negative correlation between optimal interest rate and loan management rate, and their sum is not higher than borrower’s outside interest rate. Secondly, increasing interest management rate within certain range can not only incentivize online lending platform to intensify project screening, but also raise its expected profit. Thirdly, online lending platform can obtain high expected profit from loans with large amount if she strictly screens the loan applicants, otherwise it will cause risk of credit concentration. These conclusions have theoretical and practical implication on the problem of interest rate and fee pricing and project screening for financial information intermediary.