结合BP神经网络应用平均影响值（MIV，Mean Impact Value）方法来说明如何使用神经网络来筛选变量，找到对结果有较大影响的输入项，继而实现使用神经网络进行变量筛选。-BP neural network application with the average impact value (MIV, Mean Impact Value) method to illustrate how to use the neural network to filter the variables have a greater impact on the results found in the input items, and then realized using the neural network variable selection.