Null compensator method is a popular aspheric surface testing method. However null compensator has the characteristics of complex structure, high price and poor universal property. This paper proposed to test aspheric surface by a partial compensation lens (PCL) to overcome the defect. This novel PCL method is designed to partially compensate the wave aberration caused by the aspheric surface, which allow some residual wave aberration exists. Research was conducted on measurement principle, design method of PCL. The experiment results show the feasibility and validity of this method.