Abstract: On the basis of studying the second correlation method in time delay estimation, in order to further improve the availability of the second correlation method under lower signaltonoise ratio conditions, combined with the generalized weight function in generalized crosscorrelation, the two cross-correlations in the second correlation method are weighted with SCOT separately. The experimental simulation results show that compared with the second correlation method and the generalized second correlation method, the time-delay estimation algorithm based on SCOT double weighted second correlation still has a high accuracy of time delay estimation when the SNR is low.