The invention discloses a method for controlling the eutrophication of landscape water supplied by regenerated water and belongs to the technical field of water pollution treatment. The method comprises the following steps of: by combining iron oxyhydroxide filtration with a reoxygenation biologic coast filter, reducing the concentration of phosphorus in the regenerated water entering the landscape water to below 0.05mg/L; setting the reoxygenation biologic coast filter on one side of the landscape water; removing nutrients such as the phosphorus, nitrogen and the like in the regenerated water, partial dissolved organic matters, microorganism metabolites, partial natural organic matters and the like by microbiological degradation; further purifying the water quality of the landscape water; and allowing the water from the coast filter to flow back to the regenerated water inlet of the landscape water so as to form water power circulation for the landscape water. In the method, by combining source control and internal purification, the eutrophication of the landscape water is controlled and the ecological environment of the landscape water is maintained, so that environmental pollution problems characterized by heavy organic pollution, serious water eutrophication, outbreak of blue-green algal blooms can be effectively solved.