For the low-speed high-power mine permanent magnet direct-drive motor with high harmonic content, multi-physics coupling, complex fluid field and other characteristics, the motor components are heated and the magnetic field distortion is serious. For 500 kW and 60 r/min fractional slot concentrated winding mine separation loss analysis of the permanent magnet direct drive motor is carried out. According to the calculation results, the stator copper loss accounts for the highest proportion of total loss, followed by the stator core loss and the rotor permanent magnet loss. According to the loss characteristics, the water jacket base is installed outside the motor, and the internal passage is passed. The fan forms a cooling system structure for the circulation air path. In the cooling system, the copper loss and iron loss of the stator are transmitted to the machine base through heat conduction; the stator core and the water jacket base adopt a heat jacket structure to increase the heat transfer effect; the heat of the stator end is transmitted to the straight line through the copper winding, and then stator core is transported away, and the heat of the rotor permanent magnet is carried to the stator core yoke portion by the plated block and the rotor yoke laminated structure, and is carried by the base cooling water. Iterative calculations verify that when a given inflow temperature is reached and the stator stator inner diameter is thermally insulated, the rotor heat is applied to the stator yoke hole, and the rotor air gap air temperature is loaded to the inner diameter surface of the stator, and the motor components substantially reach thermal equilibrium. The motor′s stator axial 1/2 half-tooth half-slot and the rotor radial 1/8 are intercepted. The Realizable k-ε model is used to simulate and analyze the three-dimensional temperature field of the model object under the cooling system. The results show that the low-speed high-power mine permanent magnet direct-drive motor can effectively reduce the heat generated by the stator end and the rotor magnet under the synergistic effect of the cooling system, reduce the uneven heating of the winding caused by the rotor and the copper loss of the stator, and ensure the stator of the motor. The main electromagnetic components such as windings and rotor permanent magnets operate stably in the safe temperature range, which provides a theoretical basis for structural optimization of low-speed high-power permanent magnet direct-drive motors.