Flat wire winding can greatly improve the performance of permanent magnet synchronous motor. Due to the inherent characteristics of flat wire winding, it may lead to significant eddy current loss and overheating, which will adversely affect the overall efficiency of the motor. This paper takes the flat wire winding permanent magnet synchronous motor as the research object. Firstly, according to the basic principle of motor design, by considering the performance index of the motor, the main structural parameters of the motor are determined. Then the Motor-CAD software is used to carry out finite element analysis of flat wire windings of different structures, and the loss and efficiency of flat wire motor under different cases are compared to obtain the optimal case and complete the structural optimization of flat wire windings.