Abstract: In view of the problems existed in triangular carrier control strategy and hysteresis control strategy used by SAPF, the paper proposed a design scheme of SAPF based on improved hysteresis control strategy. It analyzed structure and principle of SAPF system, introduced ip、iq harmonic detection method based on instantaneous reactive power and gave control principle of the improved hysteresis control strategy. The simulation result showed that the SAPF has good performance of harmonic current compensation.