To address the problems of thermal damage to a workpiece surface caused by the instantaneous high temperature during grinding and the difficulty in monitoring temperature in real time,the temperature field in the case of composite surface grinding by a cup wheel is studied.In order to predict the grinding temperature,considering material removal and grinding force distribution,a non-uniform heat source model with different function distributions in the circumferential and radial directions in the cylindrical coordinate system is first proposed;then,the analytical model is deduced and the numerical model of the temperature field is established based on the heat source model.The validation experiments for grinding temperature field are carried out using a high-definition infrared thermal imager and an artificial thermocouple.Compared to the temperature field based on the uniform heat source model,the results based on the non-uniform heat source model are in better agreement with the actual temperature field,and the temperature prediction error is reduced from approximately 23％ to 6％.Thus,the present study provides a more accurate theoretical basis for preventing bus in cup wheel surface grinding.