In order to solve the ventilation and heat dissipation problem of highpower and lowspeed asynchronous motor effectively, based on the heat flow coupling simulation analysis and calculation method, a 2 800 kW and 8pole ninephase asynchronous motor was taken as an example to analyze the distribution of air and temperature rise distribution in the motor with the width distance of the stator tooth platen of the top suction forced aircooled motor. As well as the influence of internal wind resistance characteristics, the matching scheme was screened. At the same time, the heat transfer characteristics of the ninephase subtracted thin insulating structure and the threephase high voltage insulation structure were compared and analyzed. Finally, the motor temperature rise experiment test was carried out, the temperature field calculation results were in good agreement with the test results, verifying the analysis and calculation of the accuracy and effectiveness of the simulation based on heat flow coupling.