The invention discloses a method for biologically remediating a water body and soil comprehensively utilizing resources. The method comprises the steps: (1), determining main pollutants in a selected land area or water body area; (2), selecting to plant and/or cultivate fast-growing herbaceous plants, fast-growing alga, trees, bushes, fungi or microorganisms with high remediation efficiency in the selected land area or water body area; (3), harvesting or collecting the fast-growing herbaceous plants and the fast-growing alga after growing to reach a suitable height or size; (4), concentratedly processing the harvested or collected fast-growing herbaceous plants and the fast-growing alga, and comprehensively utilizing to prevent the pollutants from dispersing; (5), remediating an eutrophic water body by adopting an artificial floating island; (6), remediating a heavy metal polluted water body by confining floating plants; (7), repairing cadmium and zinc polluted soil by mixed-cropping festuca arundinacea and bluegrass; (8), remediating polycyclic aromatic hydrocarbons (PAHs) polluted soil by mixed-cropping alfalfa and italian ryegrass; and (9), extracting and recovering silver from silver-containing wastewater remediation plants.