The invention discloses a method for building river course ecological restoration vegetation. The method comprises the following steps of: (1) restoring submerged vegetation: planting submerged plants with high pollution resistibility such as hornworts, hydrilla verticillata and the like in an entire engineering region in a dispersed way to restore and rebuild submerged vegetation; (2) planting riparian plants: planting emergent aquatic plants and rooted floating plants such as meadow rush, scirpus yagara, scirpus tabernaemontani, thalia dealbata, calamus, cattail, rumex dentatus, ranunculus sceleratus, water-garden iris, monochoria korsakowii and the like respectively on river sloping banks in the entire engineering region to restore and rebuild a sloping bank and riparian emergent aquatic plant community; and (3) restoring flood land vegetation: comprehensively restoring flood land vegetation such as reed, cyperus glomeratus, wire grass, festuca elata, dallas grass and the like in the entire engineering region except a part of building land. Due to the adoption of the method, the ecological problems of pollution and degeneration of river course water quality, poor river self-cleaning capacity, sharp fall in biodiversity and the like are solved effectively, and a practicable and effective ecological restoration measure is provided for natural restoration and rebuilding of a river course.