Chinese railway lines are widely distributed in the windy and snowy areas. The study of the deposition characteristics of snow crystal on the surface of the cantilever insulator is of great significance in preventing snow flash in the winter and improving the reliability of power supply. In this paper, the finite element simulation software was used to simulate amount of snow crystal deposition of railway insulators under wind speed. The velocity and static pressure distribution of flow field on insulator surface are calculated to analyze the influence of wind speed, wind direction and snow crystal type on the surface deposition of insulators. The simulation results show that the snow crystal type has little effect on the insulator amount of snow crystal deposition under the same wind speed and direction. Solid dendritic snow crystal deposition is the largest. The amount of snow crystal deposition of insulator was installed horizontally increased with the increase of wind speed and the amount of snow crystal deposition of insulator was installed obliquely increased first and then decrease with the increase of wind speed, When the wind angle is negative, the installation method has a serious impact on the snow crystal deposition. The relationship between amount of snow crystal deposition on the surface of insulator and wind direction presents a “V”-shaped distribution when the wind speed was 10 m/ s and wind direction was within ±45°. The snow crystal deposition distribution on the surface of shed increases with the increase of the wind direction, and the snow crystal deposition on the windward side of shed is larger than that on the leeward surface of the shed.