Abstract: The optimizing analysis of bracing system for a deep ex cavation is a quite complex system engineering which relates to many target factors of safety and feasibility, less cost construction, environment protection and project construction etc. A deep excavationcs evaluation target system is established, every target factorcs weight is defined by AHP method and the the fuzzy complex evaluation method is applied to evaluating the superior and inferior degree of the bracing system schemes for the deep excavation and then the optimum scheme is obtained.