Transmission line is one of the most important parts of power network, and its operating safety is the guarantee of the power network's operating safety. The operational accidents on transmission line are mainly caused by lightning accidents. Therefore, grasping the rules of lightning activity on transmission line and studying on lightning current amplitude have very important guiding significance to lightning protection on transmission line. In this paper, the method of interval division is used to improve the prediction model of mine current. And the adaptive neural network algorithm is applied to predict the number of lightning current in the lightning current amplitude of the designated transmission line.