Abstract: This article proposes a high-precision phase selection and closing control method based on voltage waveform prediction, aiming to solve the problem of large closing angle deviation in traditional mechanical phase selection switches and meet the demand for high-precision closing control in modern industry. By introducing DSP(Digital Signal Processor) technology and utilizing waveform zero point prediction algorithm and average filtering method, accurate prediction and real-time monitoring of voltage waveform zero crossing points have been achieved, thereby improving the accuracy of closing control. The experimental results show that the proposed control method effectively reduces the deviation of the closing angle and improves the overall performance of the system.