Abstract: Ultrafiltration membrane is an application of membrane separation technology, which is mostly used in environmental water treatment engineering. It can effectively filter out impurities in water, improve the cleanliness of water quality and ensure that the water quality meets the national environmental protection requirements. With the development of social economy and industry, it also caused serious water pollution.The application of ultrafiltration membrane technology can effectively purify sewage and promote the rational utilization of water resources, which is of great significance to the realization of social sustainable development. Therefore, in the environmental treatment, we should pay more attention to the application of ultrafiltration membrane technology, so that ultrafiltration membrane technology can better serve the environmental treatment project. Based on this, this paper expounds the principle and characteristics of ultrafiltration membrane application technology, and analyzes the specific application of this technology in water environment treatment.