The project is located on the bank of Sanlihe River, Hedong District, east of Qian'an City, Hebei Province. The project will organically combine sewage interception and treatment, urban land development and ecological environment construction, and drive the reconstruction of the old city and the construction of the new city through landscape construction; The belt green space shall be constructed as an ecological infrastructure to give play to the comprehensive ecological service function of landscape as an ecosystem. Covering an area of about 135 hectares, it stretches 13.4 kilometers in length and 100-300 meters in width. It is a belt shaped green park. The upstream of the park flows through the city from the Luanhe River and then returns to the Luanhe River. After two years of design and construction, the "Longxu Valley", which suffered from serious industrial pollution and caused pain to the people of the city, seems to have restored the urban ecological corridor that was "connected by reeds and lotus, rich in fish and turtles, and beautiful in scenery".