In order to reduce the active power loss and improve the compensation performance of high-voltage active power filter, an improved hybrid cascade multi-level topology is proposed, which is equivalent to series between voltage source and current source. The voltage source is constituted by hybrid cascade 27-level converter. The fundamental component of the output voltage offsets the high voltage power grid’s voltage, thus provides a low voltage situation for the current source. The current source is constituted by PWM converter, which has small rated power and high IGBT switching frequency, which makes the active power filter have excellent compensation performance. The main power of the APF is output by the square wave converter which has 50/60 Hz switching frequency, thus making the APF have small total loss. Theoretical analysis and simulation results show the effectiveness of the new topology.