In this paper, the multi-physical field simulation technology of electromagnetic induction heating motor hot sleeve is studied, and the electromagnetic -temperature -displacement multi-physical field coupling is fully considered in the whole process hot sleeve. Simulation of transient temperature distribution is compared with the measured data, and the reliability of the multi-physics simulation technology is verified. A multi-physics coupling simulation optimization design method is proposed to improve the uniformity and efficiency of the hot sleeve of the oil-cooled motor and other heating devices with high uniformity requirements. Through the prediction and analysis of thermal deformation and temperature, risk evaluation and the quantitative parameter design of the heating device is calculated. The simulation technology proposed in this paper has high practical value and feasibility. Test cost and time can be reduced, and design efficiency and reliability can be improved.