The local government and the social enterprise jointly set up a project company to sign a franchise contract with the local government for the project. The project company completes the design, financing, construction, commissioning and operation of the entire project. The project company recovers the investment through the franchise, and The share ratio shares a certain return on investment; after the expiration of the franchise, the cooperation ends and the project company hand over the sewage plant to the government. Generally, the local government invests 10% to 30% of the guiding funds in the project company and has the corresponding equity.