River course ecological system for treating non-point source low-pollution water

The invention relates to a river course ecological system for treating non-point source low-pollution water. According to the river course ecological system, ecological dirt blocking ditches are built at the two sides outside river banks of a river course, so that non-point source high-pollution water from agricultural runoff and rural sewage cannot directly enter the river course and is prevented from being mixed with river water to form into a large amount of low-pollution water to affect the river water quality; meanwhile, estuarine artificial wetland systems are built at outlets of the ecological dirt blocking ditches to forcefully treat sewage which is guided by the ecological dirt blocking pollutant intercepting ditches to enter the river course; and three-stage ecological bank protection comprising emergent aquatic plants, wetland plantsbog plants and shrubs and arbors is built at the inner sides of the river banks of the river course so as to improve the self-purification capacity of the water body in