Abstract: The lightning sound source localization system consists of four-element square microphone arrays, thunder signal transmission system, signal acquisition, recording and display device. Combined with measured thunder data, this paper applies the generalized cross correlation (GCC) time delay estimation (TDE) method to calculate time differences between signals arriving at different microphones, obtains distance between the sound source and the microphone arrays on the basis of acousto-optic difference method, and realizes three-dimensional positioning of the sound source and reconstruction of the lightning discharging channel. Compared with synchronous observed electromagnetic pulse(LEMP) fields and atmospheric electric field, it proves good positioning performance of the system.