Aiming at the heat dissipation requirements of high power density electric vehicle motor, a cooling solution of motor based on heat pipe is proposed. Through pipes, the heat can be transmitted rapidly from the end winding to housing. It is one of the effective ways that can solve the problem of high-power density on motor. The heat pipe assembling technique is designed. Using the ANSYS Fluent software, the finite element models are established for both the original motor and the heat-pipe-based motor, and temperature field simulation is carried out. Tests between the original motor and the heat pipe-based motor are established. Prototype test results are similar to the simulation results. It is found that the high temperature region of the permanent magnet synchronous motor is mainly located at the end of the winding. Simulation and test show that the design of the cooling system based on the heat pipe can effectively reduce the temperature rise of the motor winding.