Using commercial software AUTODYN, dynamic responses of a type of cylindrical rescue chamber subjected to explosion impact in the tunnel were analyzed based on the fluid-solid coupling method. Simulation results show that under 2.14MPa peak pressure of the impact load, maximum equivalent stress generated by front end face shock and back end face shock were below the ultimate strength respectively; both maximum displacements of center on the blast front did not exceed the requirements of failure criteria. The above results demonstrated the strength of the rescue chamber met national standards. When the blast front was changed to a plane structure, strength failure and deformation failure occurred under the exact same explosion impact, which illustrated the better impact resistance of the protruding structure. The results provide scientific foundation for design modification and safe use of chambers.