The invention discloses a method for preparing an anti-corrosion composite coating on the surface of a steel plate. The method comprises the steps that 1, degreasing cleaning is carried out on the surface of the steel plate, and then cathode activating treatment is carried out; 2, the surface, obtained after cathode activating treatment, of the steel plate is electroplated, drying is carried out after cleaning, and the steel plate with a nickel transition layer on the surface is obtained; and 3, metal titanium powder is adopted as powder, a synchronous powder feeding manner is adopted, laser cladding treatment is carried out on the surface, with the nickel transition layer, of the steel plate, a titanium surface layer with the thickness of 0.5mm-1.51 mm is obtained on the surface of the nickel transition layer, and after cooling is carried out to room temperature, the anti-corrosion composite coating is prepared on the surface of the steel plate. The anti-corrosion composite coating prepared on the surface of the steel plate is composed of the nickel transition layer and the titanium surface layer, and is dense in structure, flat and smooth in surface and good in corrosion resistance and is combined with a base body well, and the corrosion resistance of the surfaces of steel materials for oceanographic engineering can be remarkably improved.