The invention provides a method for improving service functions of urban lake ecosystem landscapes. The method comprises the following steps of (1) spraying polyacrylamide into a target water body, sothat the concentration in the water body can reach 5 to 20mg/L; after two months, spraying entozole into the target water body for two to three times, wherein the dosage is 0.1 to 0.5g/m<2> each time; after one month, spraying sodium naphthyl acetate into the target water body for two to three times, wherein the dosage is 0.5 to 1g/m<2> each time. The method has the characteristics that accordingto the problem of submerged plant landscape in the urban lake water body, the height of the lake submerged plant is inhibited, and the root is strengthened, so as to reach the purposes of optimizingof submerged plant landscapes in the urban lake water body and stabilizing of colonies; the safety effect is realized, the cost is low, and the like.