The thermal balance characteristics of mining reducers have an important influence on the sealing performance of reducers and the service life of gear transmission parts. Through the heat balance design of the reducer operating under low temperature conditions, the parameters of the reducer heating and cooling system were determined, and the design of the heating and cooling system was carried out. The practical application showed that the reducer had good performance, which proved the reliability of this method and was of great significance for the optimal design of the reducer.