aiming to the problem that pulse noise and white noise have an influence on accurate extraction of transient power quality signal, a effective filter algorithm is proposed to filter out noise to great extend on the basis of keeping effective components of signal. This algorithm is based on multiple structure elements composite filtering of morphology LMS. This paper utilizes voltage sag、voltage surge and voltage interrupt and so on to carry out simulation experience. The simulation results show that the SNR which the algorithm based on multiple structure elements composite filtering of morphology LMS gains is about 1.10 times than that of multiple structure elements self-adaptive and composite algorithm and about 1.1 times than that of wavelet transform. In other words, this algorithm not only effectively filters out noise of transient power quality signals, but it can remain characters and shape of disturbances.