Abstract: To study the mechanism and conditions of tunnel's large asymmetric deformation, we analyzed long-term large deformation mechanism of deep roadway, studied the difference of different strength surrounding rock's deformation and failure under high stress field, studied the influence of surrounding rock's attitude, layered structure on the deep tunnel's large asymmetric deformation by numerical simulation method. The results show that the deformation difference of surrounding rock with different strength in tunnel section under high pressure field is the main reason for deep tunnel's large asymmetric deformation in inclined, layered and property different surrounding rock's spatial structure. The asymmetric surrounding rock structure and strength caused the deep tunnel's asymmetric deformation.