The invention discloses a high-precision phase-selection control device, which is characterized by comprising a signal collection unit, a central processing unit, a control output unit, a communication unit and a human-machine interface display; the signal collection unit comprises a low-pass anti-aliasing filter module, an analog/digital (A/D) conversion module and a frequency tracking measuring module; the A/D conversion module is respectively connected with the low-pass anti-aliasing filter module and the central processing unit through a circuit; the frequency tracking measuring module is respectively connected with the low-pass anti-aliasing filter module and the central processing unit through a circuit; the central processing unit is connected with the control output unit through a circuit; the central processing unit is also respectively bidirectionally connected with the communication unit and the human-machine interface display through a circuit; and the communication unit is bidirectionally connected with a background host computer through a circuit. By adopting a way for measuring a voltage zero-crossing point by simultaneously utilizing software and hardware, the frequency variation is reduced, the influence of the harmonic interference on the zero-point measuring error is reduced, and the phase-angle measuring precision is improved.