The invention relates to a stress and formation analysis method for a deep foundation pit engineering structure under complex conditions. The analysis method mainly comprises the following aspects of: (1) stress and deformation analysis of a space enclosing structure during the construction stage; (2) stress and deformation analysis of an underground structure during the construction and using stage; (3) contrastive analysis of measured data during excavation of a foundation pit. Compared with the prior art, the stress and formation analysis method disclosed by the invention has the advantages of reasonable design, effective guide of site construction and abnormal situation treatment, good safety and reliability of the structure and the like.