Abstract: According to characteristics of bracing engineering for deep excavation of metro,using the theory of fuzzy mathematic and AHP(analytic hierarchy process),a fuzzy consistent matrix mathematic model was established to optimize bracing projects for deep excavation of metro.The model was based on clear concept and rigarous theories,and could be applied extensively to obtain objective and dependable result.A case study showed that the method was reasonable and effective to optimize bracing projects for deep excavation of metro.Compared with other methods,the present method could be used to handle all kinds of complicated decision problems,and was apt to establish the computer procedure.