River channel ecological filtration system and construction method thereof

The invention discloses a river channel ecological filtration system. The river channel ecological filtration system comprises a gravel filtration area, a plant restoration area and an ecological bag restoration area. The ecological bag restoration area comprises at least two sludge ecological blocks, the sludge ecological blocks are arranged along both sides of a river channel in a staggered mode, each sludge ecological block comprises a substrate and a protecting portion arranged on the corresponding substrate, each protecting portion comprises at least two layers of sludge ecological bags arranged in the direction parallel to a slope, and a connection buckle is arranged between every two adjacent sludge ecological bags in a crossing mode. The invention further discloses a construction method of the river channel ecological filtration system. The construction method comprises the construction step of the gravel filtration area, the construction step of the plant restoration area and the construction step of the ecological bag restoration area. Sludge is cleaned away and meanwhile turned into treasure on site, the sludge difficult to treat and accumulate is used, the ecological restoration technology is adopted, local dominant aquatic plants can grow in sludge ecology, the water ecology restoration function is enhanced while slope protection is conducted, and double purposes are achieved at one stroke.