When a plane flies under freezing weather conditions, it is prone to icing on the surface because of the impact of supercooled water droplets in the clouds. Icing of aircraft seriously endangers flight safety, and accidents caused by ice accretion occur frequently. To deal with the icing, aircraft is usually equipped with anti-icing systems. With the development of the composites, the composite electric anti-icing system has become the frontier research direction in this field. Numerical simulation method was used to study the system in this paper. The most difficult part of the simulation was to simulate the anisotropy of the composite. Fluent's user-defined scalers (UDS) was introduced to simulate the multilayer anisotropic thermal conductivity of composite materials. It is of great significance to the application of composite electric anti-icing icing system.