Hybrid active filter has become a study focus these years. In this paper introduced a simple, practical kind of topology importantly. It analysised the parameter selection methods about each part of HAPF, and describes the suppression measures of voltage spike during switching off.It is shown from the simulation results that the HAPF combining the PF with APF is recommended.The capacity of the system decreases to a great extent.Meanwhile the good performance of displacement power factor and current harmonics compensation is verified by the results.