DC voltage control is the key to guaranteeing the performance of active power filter（APF）.A fractional-order PIλ（FO-PIλ）controller is proposed to realize the stability control of DC voltage of APF using the DC voltage power model in the direct power control（DPC）system.The FO-PIλ controller is designed with the frequency-domain method，and is used to regulate the value and fluctuation of the DC voltage to reduce the bad influence on the power loss and compensation performance of APF.The simulation results show that the DPC system of APF based on the FO-PIλ controller has good dynamic and robust performance，and the DC voltage remains stable during impulse-voltage and load-change.The DC voltage stabilizes at the given value quickly and accurately.The new control strategy is better than that using the traditional PI controller.