The functions of the static reactive power compensation device (SVC) are expanded, and its functional improvement in waveform recovery is analyzed. Under the assumption that the system voltage is a pure sine wave, the ideal compensation current of the static reactive power compensation device (SVC) is discussed from three aspects: theoretical analysis, online algorithm and experimental observation, and the computer simulation experimental process under normal conditions is given. Experiments show that using ideal compensation current as the output control signal of SVC has the advantages of fast response, good smooth adjustment performance and high compensation efficiency, and has certain practical value.