Abstract: Blind signal extraction algorithm is a hot research field of blind signal separation. For the large computation of present algorithms, this paper uses the asymmetric of skewness as the cost function to evaluate the non-Gaussianity of a signal. The algorithm reduces the computational complexity greatly, and sloves the problem of order uncertainty. Further, according to the skewness interval of the interested signal, the algorithm combines SUMT-exterior penalty method and skewness-based algorithm, proposes a novel cost function based on priori information of skewness, and achieves the blind extraction of the interested signal. Computer simulation and experiments on acoustic signal confirm the effectiveness of the algorithm.