In order to optimize the speed control effect of three-phase AC asynchronous motor, the speed control method of three-phase AC asynchronous motor based on BP neural network tuning PID control is studied. The mathematical model of the three-phase AC asynchronous motor is constructed. After the three-phase AC asynchronous motor is transformed into a computer analytical calculation mode in the mathematical model mode, the current operating speed of the three-phase AC asynchronous motor is measured by the speed tracking measurement method of the three-phase AC asynchronous motor. The speed control method of three-phase AC asynchronous motor based on BP neural network tuning PID control is adopted to realize the speed control of three-phase AC asynchronous motor. The experimental results show that the proposed method can accurately measure the current running speed of three-phase AC asynchronous motor and complete the speed regulation of three-phase AC asynchronous motor within 15 s. It has significant application value in similar methods.