Abstract ： Research purposes ： In the excavation of the exit of Hantangpo tunnel, local cracking appeared at the surface of the slope，many cracks appeared in a curved distribution within 50 meters on the right side of the tunnel (the side near the hill). The width of the crack is 0. 1 ?5 cm, the maximum length is about 30 meters and the maximum visible depth is about 0. 45 meter. For the safety of the tunnel engineering，this article makes numerical simulation analysis of slope body and tunnel under different conditions based on field deformation observation data and field mapping, and then studies the deformation characteristics of tunnel and slope under different protective measures，which can provide design basis for the subsequent protective measures of tunnel excavation. Research conclusions:( 1 ) The Hantangpo tunnel is a shallow bias tunnel located in fault fracture zone. After the preliminary support of excavation，the deformation of the tunnel extended to the surface because of the tunnel bias and the broken rock mass， causing the surface cracking on the slope. (2) For the subsequent protective measures， the tunnel lining support strength should be improved and the backfill measures should be taken at the toe of the slope. The piles should be set at the left side of the tunnel if the deformation continues to develop in the subsequent construction process. After expert review, the measures of strength support and toe backfill can effectively control the deformation of tunnel and ensure the construction safety. (3) The research results can be applied to railway, highway, hydropower and other industries tunnel projects which can provide design basis for the protective measures of those similar shallow bias tunnels in fault fracture zone.