Abstract: The wing-monopile is a new structure of the offshore wind turbine generator foundation, on which there are few studies. Based on ABAQUS three-dimensional numerical simulation model, the horizontal bearing performances of the large diameter monopile and wing-monopile were analyzed and compared under the conditions of the horizontal loads, including the bending moment, stress, displacement, inclination rates of pile at mud surface, ultimate bearing capacity and failure mode of the pile. Based on the calculation results of soil pressure distribution on the pile and the mechanism of soil-pile interaction, the P-Y curve of the large-diameter monopile in soft clay foundation was developed by referring to the P-Y curve model in the current specification, and the correlation coefficient was corrected. According to the research results of the influences of the area, shape, stiffness and buried depth of the wing plate on the horizontal bearing capacity of the wing-monopile, the empirical formula and the calculation formulas of the correlation coefficients of the ultimate bearing capacity of the large diameter wing-monopile in soft clay foundation are presented by referring to the specifications for the bearing capacity of the large diameter monopile, which can provide a technical support for the research and application of the wing-monopile in the marine environment.