The principle and algorithm of artificial neural network were used to select some meteorological factors to established the BP network model of occurrence area and population density of Dendrolimus superans and meteorological factors in Elunchun Zizhiqi of eastern Inner Mongolia, based on the correlation coefficient method and the stepwise regression method for selecting the evaporation, temperature, wind speed, relative humidity and others as the forecast factors. The results showed that the established model had higher prediction effect. The reasonable forecast factors matched with the facts. The error was small, which was controlled between 0.1%-25.0%. The model could be used as the basis for integrated pest management.