During the shield tunnel excavation through the complex environment with many kerst caves，stress field of karst cave can ke changed suddenly. Moreover，it also resulted in engineer disaster，such as cave collapse， water dashes forward in karst area. The finite element emulation method is used in the paper，and two important factors for the numbers and the arrangement of the caves during excavation is simulated. Displacement field， stress field and plastic zoon of the surrounding rock of tunnel are analyzed. The results are as follows: The existence of karst caves greatly increases the maximum principal stress of the tunnel surrounding rock； The vertical displacement of the surrounding rock increases with the number of caves；The stress field， displacement field and plastic area of surrounding rock have different changes according to the relative position of the tunnel. The results can provide theoretical and engineering guidance for the design， construction and operation of shield tunnel in karst region.