Abstract: In order to eliminate me harmonic currents from me currents generated by electrical a11d electronic apparatus， the design method of a single—phase shunt active power filter (APF) based on the active energy balance was proposed. For it was difficult to measure me hamlonics in single-phase system， the traditional method for harnlonics measurement was abandoned． In this method，the harnlonic wave compensation could be easily realized by sampling and controlling the source current and DC voltage of the filter． The double-closed control loop was emendated． The model of APF was built and simulated using the simlIladon software Saber，and an active power filter was designed. The simulated and experimental results indicate that the total harmoic distortion is less man 10％．