Many active faults exist in the west of China, especially strike-slip faults; thus, passing through active faults is inevitable during tunnel construction, and the stability problem of tunnels becomes an important research topic. To investigate pivotal issues caused by active faults, such as the failure modes of tunnels, considering Xianglushan tunnel as a backing project, this study examined the response law of a tunnel under a strike-slip fault in virtue of model experimental test and numerical analysis, which is a comprehensive method. On the basis of the prototype tunnel, a numerical analysis model was established to acquire the failure mode of deformation, the distribution of stress, and the internal force of lining under the dislocation of the strike-slip fault. Meanwhile, a model experimental test was performed under the strike-slip fault to monitor tunnel deformation and failure, strain distribution, ground deformation, and crack caused by the fault. First, the results of the model test were in good agreement with the numerical analysis, indicating that the liner maintains high stress state near the fracture surface but low stress state in its ends. The west haunch of the hanging wall and the east haunch of the footwall presented a tensile failure. Moreover, the east haunch of the hanging wall and the west haunch of the footwall reaching fault trace suffered in press condition lightly. According to the result of the numerical analysis, the tensioned zone of the lining was distributed along the longitudinal direction of the tunnel, which mainly focused on the longitudinal position of the wall on both sides of the tunnel in the range from 0.5 D (D is the diameter of the tunnel) to 2 D away from the fracture surface in the footwall and in the same range in the hanging wall. Second, the wrinkling range of ground was from -2.4 D to 1.3 D in the model size according to the model test. Furthermore, the failure form of lining under the strike-slip fault is a kind of combined failure, including tensile failure and direct shear failure, but shear failure is the main failure form. Last, the affected zone of lining was wider within the hanging wall than the footwall. Therefore, the footwall under the fault dislocation is the control point to resist such dislocation. This research provides a reference for the fortified range of the tunnel crossing a strike-slip fault with certain practical significance.