Both domestic and foreign experience have shown that megacities must form a suburban railway system based on commuting as the main functions and combined with TOD land development，and the relevant consensus should be transformed into tangible action as soon as possible. It is necessary to change the idea that Beijing urban rail transit relies too much on the subway and can only use the national railway resources to develop suburban railways，and build a suburban commuter rail system with radial corridors as soon as possible to reverse the passive situation of the sprawling development of the Beijing metropolitan area.