The PPP investment model has been widely used in the field of domestic infrastructure construction.It is necessary and important for the consulting engineering companies to select the appropriate investment and financing model.This paper focuses on the investment and financing model design for consulting engineering companies to operate river comprehensive regulation PPP projects.The investment and financing model chosen on the one hand needs to meet the needs of the project itself,on the other hand it needs to be in compliance with the policy to achieve legal compliance.Taking the S River governance PPP project as an example,the paper analyzes the operational advantages of the project’s investment and financing mode,describes the impact of the current policy on the project,and the adjustment measures,and analyzes the project’ s implementation results.It is necessary to follow the policy,make measures according to local conditions,take advantage of the situation,advance gradually and entrench oneself at every step for the consulting engineering company to implement the investment and financing of PPP projects.