To efficiently and accurately locate the buried gas pipe leaks, a three-dimensional ( 3D) localization method for the leakinduced vibroacoustic source based on the grey wolf optimization (GWO) and the dual-wave spectrum estimation 3D is presented. A dual-wave spectral function is formulated by using the mixed signal model of P1 and S waves detected by a ground-mounted accelerometer array. The velocity is estimated by using the dual-wave velocity pairing based on the superimposing characteristic of dual-wave peaks. Then, the estimated velocity is substituted into a 3D spectral function to perform 3D localization. Considering the 3D spectral function as a fitness function, the procedures of dual-wave velocity pairing and 3D localization are optimized by using the GWO algorithm to replace the grid search for 3D spectra. Experimental results show that the presented method can accurately estimate the velocity at which the leak-induced vibroacoustic wave propagates along the soil, and thereby locating the underground leak. Compared with the conventional method using 3D spectrum search, the localization accuracy of the presented method is increased by 25. 85% , and the search time for 3D spectra is decreased by 99. 95% .