The invention provides a motor cogging torque optimization method, a motor structure and a motor. The motor cogging torque optimization method comprises the steps that a number of cogging torques at different stator slot circle radiuses at a stator iron core circle radius R; the stator slot circle radius r corresponding to the minimum cogging torque is determined; the proportional relationship between the stator slot circle radius and the stator iron core circle radius is determined; and the stator structure of the motor is determined according to the proportional relationship. According to the invention, when the motor is designed, the stator structure is determined according to the proportional relationship; the cogging torque of the motor can be remarkably reduced; the motor positioning accuracy and the response speed can be greatly improved; and the motor cogging torque optimization method can be applied to the design of various servo motors.