Abstract: In the mathematical model of the seven-element acoustic array,the first-order discrete wavelet time delay estimation algorithm estimate the delay time poorly in low SNR environment,this paper proposed the lifting wavelet time delay estimation algorithm to try to solve the problem.Compared with the first-order discrete wavelet time delay estimation algorithm,this algorithm improved the precision of positioning in low SNR environment.The computer simulation showed that this algorithm improved the efficiency of the computation and enhanced the accuracy of positioning in the seven-element acoustic array.