Catering wastewater is mainly a mixture of various kinds of wastewater generated in the business process of the catering industry, including swill and swill generated in the process of washing vegetables, rice, cooking and cooking, and washing dishes and chopsticks. The direct discharge or substandard discharge of catering wastewater will cause great pressure on urban sewage treatment plants. In areas with imperfect pipe network, the problems are more prominent. If this kind of wastewater is directly discharged into the nearby water body, it will not only cause pollution, eutrophication and other problems, but also pose a threat to human physical and mental health.