Along with the rapid development of economy in our country, the space that a city can take advan. tage of becomes less and less. Thus, it is necessary to develop underground buildings, using deep foundation pit supporting. How to guarantee the security and the rationality of the deep foundation pit has become the important problem in the design of deep foundation pit. Based on the engineering example and using the calculation software of geotechnical principle of deep foundation pit and the finite element analysis software Midas GTS-7.0 to analyze the security of foundation pit, its analysis results can provide reference for optimization design and construction of similar projects.