In a static synchronous compensator（STATCOM） with LCL filter， the traditional control method by using inverter-side current as feedback does not consider the impact of the filter capacitor current， thus the reactive power compensation ability of STATCOM declines. To solve this problem， a method to calculate the STATCOM network-side current by using the inverter-side current is proposed.By using the calculated network-side current compared with the reference current as feedback， the impacts of the filter capacitor current is reduced， and the reactive power compensation ability of STATCOM is improved. The stability of the control system is analyzed， and a simulation model is established. Simulation results show that the proposed control method is correct and superior.