On account of the traditional multiple signal classification (MUSIC) algorithm has poor performance in time delay estimation under the condition of small sampling data and low SNR. In this paper, the traditional MUSIC algorithm is improved. The algorithm combines the idea of spatial smoothing, constructs a new covariance matrix using the covariance information of the measurement data, and constructs a weighted value using the modified noise eigenvalues to weight the traditional estimation spectrum. Simulation results show that the im-proved algorithm has steeper spectral peaks and better time delay resolution under the condition of inaccurate path number estimation. The time delay estimation accuracy of this algorithm is higher than that of the traditional MUSIC algorithm and the improved SSMUSIC algorithm under the conditions of small sampling data and low SNR.