The simulation analysis of a new inlet hole of a novel permanent magnet magnetic coupling wing cooling device is carried out. Firstly,the computational fluid dynamics software Fluent is used to simulate thermal field and flow field flow of three inlet opening holes of same area and same location,the optimum solution could be obtained through analyzing its maximum temperature rise and resistance. Secondly,the selected air intake scheme is tilt open holes,optimum tilt angle could be found by analyzing the relationship between different tilt angles from the maximum temperature rise and resistance. Finally,optimum aperture opening number could be selected by arranging the different number to analysis. Comparative results show that reasonable opened tilt inlet hole,the maximum temperature rise of the permanent magnetic coupling and the overall maximum temperature rise inside the permanent magnet could be effectively reduced,the temperature distribution in permanent is changed,the central hot zone temperature of outer rotor is reduced. It has some practical value.