Paper define the relation to grade highway distance and highway class ( two outputs ) and population and equal gdp ( two inputs ) by using neural network , and after conducting calculation , obtain a family sciatica result that highway distance of zheng zhou city will arrive at 8038 kilometer , it has been accepted by interrelation department 论文采用神经网络方法来确定等级公路里程、公路等级(两个输出)与人口、人均gdp (两个输入)的关系,进行计算得到, “到2020年郑州市的公路里程将达到8038公里,同时公路等级也上升为0 . 443 ”的比较科学的结论,得到有关部门的采纳。