To improve the reliability and accuracy of the leak localization with traditional correlator, and to make the result be verified timely, a new method of leak localization with three sensors based on multi-scale analysis is proposed. The third sensor was added to form a three sensors model in this method, and then the correlation value for time delay was calculated in every sub-band through multi-scale decomposition for signals from three sensors. According to the matching relation among these three sensors, the optimal results could be obtained which showed that this method could not only calculate speed by itself but also make the leak localization more precise.