Permanent magnet synchronous motor is widely used in industry because of its small size, low cost, high efficiency and excellent performance. Permanent magnet synchronous motor is gradually becoming an important part of numerical control system. To ensure the stable operation of permanent magnet synchronous motor is a necessary condition to ensure the stable operation of numerical control equipment. In actual production, due to the complex working environment and long working time of permanent magnet synchronous motor, stator windings of permanent magnet synchronous motor are prone to inter-turn short circuit fault. If we do not take effective measures in time, a small failure will become a major failure, resulting in the breakdown of the whole system. If the motor faults are diagnosed according to the historical operation data of the permanent magnet synchronous motor, and the life prediction of the motor winding can ensure the stable and reliable operation of the motor equipment, give full play to the performance of the motor, to reduce economic losses and avoid catastrophic accidents.