Based on EC (0.25°×0.25°) model forecast data and ADTD lightning location system, combined with the formation conditions of the three elements of a thunderstorm, the forecast factors are selected from the aspects of water vapor, unstable energy, thermodynamics and dynamics, and the weight coefficient is determined by the principal component analysis. Sichuan Province is divided into three regions (the Sichuan basin, Panxi area and Western Sichuan Plateau) according to the altitudes and the forecast model is established, respectively. The lightning grid probability prediction products are developed. The forecast test shows that the Sichuan basin has better forecast effect when the probability is 70%, and the TS scores are 0.294. The forecast effects in the Panxi area and the Western Sichuan Plateau are better when the probability is 60% and their TS scores are 0.302 and 0.299, respectively.