The temperature rise problem of magnetic suspension linear motor with transverse magnetic field, electric excitation and flux switching is studied, and the cooling system is designed to ensure the normal operation of the motor. The structure and operation principle of the motor are analyzed, and the three-dimensional steady-state temperature field mathematical model are established, and the boundary condition equation are derived. Considering the heat exchange of each part of the motor, the thermal conductivity of each material and the convective heat transfer coefficient of different parts of the motor are determined. The copper loss and iron loss of the motor are calculated by finite element method, and the corresponding heat of formation is obtained. The three-dimensional finite element method is used to calculate the temperature field under different working conditions of the motor, and the temperature field distribution of the motor core, armature and excitation winding is obtained. Finally, the cooling system is designed, and the temperature distribution under natural air cooling and forced water cooling conditions is compared, which proves the feasibility and rationality of the cooling system.