Reactive power balance of power system is important. Static synchronous compensator (STATCOM) based on invert technology is a new dynamic reactive power compensation, and has many advantages compared with static var compensator, so STATCOM has vast market prospect. New technology can improve the performance of static synchronous compensator, and in this paper wavelet filter is applied in STATCOM to filter the harmonics of load current, and the active portion and reactive portion of the fundamental current are calculated by dq transformer, and the reference signal of output current is calculated by dq reverse transformer using the reactive portion and the output of PI controller which controls the DC voltage, and PWM tracking control technology is employed. The simulation results indicate that the application effect is good.