Abstract: Due to the iterative algorithm exists depending on initial value and easily divergent for lightning location, we propose a three\|dimensional grid search algorithm using for positioning and calculating of intracloud lightning . The procedure of the three\|dimensional grid search algorithm to find the lightning location is introduced. The lightning space range is defined according to the prior condition. Through dividing space grid reasonably and using multi\|level grid search strategy to calculate the cost function value of each mesh point, the most appropriate solution of the cost function is the maximum likelihood estimator of lightning position. The validity and stability of this method is confirmed by the simulation and numerical analysis of a lightning detection network data .When the grid is divided reasonably and properly, the results must be close to the true solution after multilevel searching.