In the servo control system, the controller has a great influence on the performance of the interior permanent magnet synchronous motor (IPMSM). The time-stepping finite-element method is used to analyze the IPMSM. Both 3D and 2D transient electromagnetic field finite element models are built in Maxwell software. A model of motor control algorithm is built in Simulink software. The finite element models and motor control algorithm model are combined by Simplorer interface technology. The field-circuit coupling simulation model for IPMSM is built. The data of torque, current, loss and flux weakening speed range of the IPMSM under different control strategies and different working conditions are analyzed. It provides a reasonable method for the calculation and optimal design of the IPMSM servo speed control system.