Xinqidaoliang Tunnel under construction is the largest crosssection road tunnel with complicated geological conditions in Gansu province. Based on the monitoring data of surrounding rock deformation in the tunnel, the geological factors including the rock quality, the fault and crushed zone, groundwater, and depth and so on are analyzed in this paper. Results show as follows: 1）The worse the rock quality is, the larger deformation surrounding rock is. 2）The deformation is large and lasts for a long time in the fault and crushed zone. 3）The deformation is small if the tunnel is against the direction of uncontinuous plane. 4）The groundwater gives rise to reduction of stability and large deformation of surrounding rock. 5） The depth of the tunnel also affects the deformation of surrounding rock.