The traditional DC motor has the defects of large volume, high heating, inconvenient maintenance and low control accuracy, which seriously affects the performance of the missile steering gear. The coreless disc permanent magnet motor is is a high performance servo motor with small size, good reliability, simple structure, high power density and high efficiency. It can be widely used in the field of aerospace and navigation, mechatronics, robot and other fields. Therefore, the research on coreless disc motor will be an important development direction in the field of motor in the future. This article is based on the application background of electric actuator for missile, and develops a coreless disc type permanent magnet synchronous motor. Design the basic structure of a coreless disc motor based on the performance indicators of missile servo, and then analyze the magnetic performance, back electromotive force, and torque characteristics of the motor separately.