With the rapid development of urban subway construction, the foundation pit excavation will affect the neighboring existing subway tunnel, this paper analyzed the influence of foundation pit excavation on adjacent subway tunnel with Midas GTS numerical simulation calculation software, makes simulation analysis of the entire process of stratum weight consolidation, foundation pit excavation, the results show that the method has certain directive significance to engineering.With the rapid development of urban subway construction, the foundation pit excavation will affect the neighboring existing subway tunnel. This paper analyzes the influence of foundation pit excavation to adjacent subway tunnel with Midas GTS numerical simulation calculation software, makes simulation analysis on the entire process of stratum weight consolidation and foundation pit excavation. The results show that the method has certain directive significance to practical engineering.