The abstract introduce the most of the contamination accumulated on the insulator, it comes from the polluted particles in the air around the insulator, and most of these dirt particles are in contact with and adhere to the surface of the insulator under the influence of forces such as gravity and wind. Studying the distribution of the air flow field around the insulator can better understand the trajectory of the contaminated particles in the air and the fouling process of the insulator. Based on the fluid dynamics simulation experiment, the air flow field around the insulator and the motion of the dirty particles are studied by Fluent software. The specific implementation steps are as follows: Using the Geometry and Mesh modules of Fluent software, the model of the insulator and its surrounding flow field is established. The division of the grid; the fluid dynamics simulation calculation is performed by Fluent to solve the flow field; and the parameters are modified repeatedly according to the variables studied.The umbrella skirt of the anti-ice composite insulator is characterized by the installation of an enlarged shed that is larger than the diameter of the ordinary shed to cover the dirt and clean up the dirt by deformation. Compared with other insulators, the ratio of the diameter of the anti-ice composite insulator to the diameter of the shed is small, which also makes the flow field distribution of the insulator have the characteristics that the backflow of the leeward gas is not obvious.