In order to study the influence of bias caused by surface inclination on the stress and deformation characteristics of the tunnel, relying on the Sanqingkou tunnel engineering example, based on the plane strain problem, a total of 0 working conditions with surface inclination angles of 5°, 45°、......、10° were numerically simulated. The results show that when the surface inclination angle is less than 35°, the changes of the tunnel vault settlement, perimeter convergence, lining bending moment and lining axial force are small, while when the surface inclination angle is greater than 35°, the values increase sharply. Under the case of bias, the sensitive parts of the tunnel are the left wall foot, left wall, left arch foot, right arch foot, and when the inclination angle is greater than 35°, the bending moment of the left arch foot appears inverted (the inner side is compressed, becoming the inner side is pulled).