In order to quickly evaluate the underwater corrosion electric field in the damaged state of the submarine coating, the corrosion current equivalent circuit of submarine coating local damage was established based on the principle of electrochemical corrosion and the characteristics of submarine structure, and the corrosion current intensity of submarine coating local damage was calculated. The corrosion electric field of submarine was modeled based on the point current source. The damaged part of submarine coating and exposed propeller were equivalent to point current source. The calculation formula of electric field of point current source in layered medium was used to estimate the corrosion stable electric field in the damaged state of the submarine coating. Compared with the simulation results of the commercial finite element software COMSOL for the corrosion electric field of a certain submarine, the results show that the submarine surface corrosion current and the electric field distribution curves of different paths obtained by this estimation method are basically consistent with the simulation results of COMSOL, the relative error of current calculation value does not exceed 6.5%,and the relative error of peak to peak value of each electric field component does not exceed 18%.