Abstract: The N-S equation was used to solve the external air flow and the internal anti-icing cavity flow. The impact characteristics of the supercooled droplets were obtained by the Euler method. After the internal and external flow are stabilized by coupling heat transfer, it starts icing to achieve numerical simulation of wing hot air anti-icing and ice ridge formation. The simulation results show that when the hot air anti-icing system is turned on, the minimum temperature of the skin in the heating zone is 286 K to ensure that the heating zone has no ice, but the temperatures of the upper and lower wing surface behind the heating zone are reduced to below 273.15 K, and the water from the anti-icing zone runs here to form ice ridge. The analysis of the simulation results shows the feasibility and rationality of the numerical simulation of hot air anti-icing. However, in the case of removing the ice from the leading edge, the formation of ice ridge outside the anti-icing zone has a severe influence on the aerodynamic characteristics. Numerical simulation of the flow around the wing with ice ridge was carried out. It discloses that with a lower environment temperature, the ice ridge is higher and closer to the anti-icing zone; and with a longer icing time, the unsteady characteristics of the ice ridge are more obvious, the capture of the flow details is more difficult, and the influence on aerodynamic characteristics is more severe.