In order to improve the operation efficiency of large cities and deal with traffic problems, the rapid development of rail transit in our country, especially the construction of subway transportation has entered a phase of rapid development. The gradual formation of metro lines network and the access nodes as city scarce resources will inevitably have a profound impact on the use of urban space. By analyzing the infl uence and existing problems of metro construction on urban spatial developments in Xi’an, this paper discusses the optimization of urban space environment and basic methods of urban design based on the subway construction.