Abstract: To study the deformation characteristics of typical underground tunnels under non-axisymmetric external load conditions, based on the analytical solutions of circular and non-circular tunnels, the influencing factors of tunnel wall stress and displacement are summarized. Using numerical simulation, establishes three discrete element models of non-circular caverns under variable lateral pressure coefficients, and obtains the stress, displacement, and fracture distribution patterns of the cavern rock mass. The results indicate that for circular caverns, the stress difference on the wall is the greatest and they are most prone to failure. The variation of total stress concentration coefficient is a monotone function of variable lateral pressure coefficient .The radial displacement plays a leading role in the stability of surrounding rock. For non-circular caverns, the dominant displacement of surrounding rock changes from vertical displacement to horizontal displacement when the pressure measurement coefficient increases. When the side pressure coefficient changes from 0.5 to 1.0 to 2.0, the maximum principal stress is transferred from the side wall to the vault, and the minimum principal stress is always concentrated around the hole in the side wall. Under the same external load and pressure coefficient, the surrounding rock failure form of Chengmen cave is simple and the plastic zone radius is small, the surrounding rock failure form of rectangular cave is complex and the plastic zone radius is large, and the plastic zone radius of oval cave is maximum when the side pressure coefficient<1.