Taking the Bijiashan tunnel under construction in Chongqing city as prototype and geometric similarity ratio of 1:25 is adopted in model test, then selecting cavity of 60 range in arch crown of level III surrounding rock as the objects, the research is carried out. During the model test, firstly, applying the load on the structure till it produces the defects, and then applied load again while the structure is destroyed after taking different inner surface reinforcing at the same rock mass and load form in tunnel; the bearing capacity of structure is researched emphatically while it's failed in different inner surface reinforcing material and range. And the distribution of internal forces and forms of failure for secondary lining in different reinforcing manner are obtained; and finally, the reasonable conclusions are drawn so as to offer instruction opinion for maintaining and reinforcing in future.