Ten typical cracks are selected from 80 crack monitoring points of a highway tunnel, and the comprehensive evaluation method is used to evaluate the safety of the cracks. The dangerous crack cross-sections are obtained, the finite element model of typical fracture cross-section is established by Midas/ GTS, and the bearing capacity and safety factor of tunnel lining structure are calculated. The calculation results show that when the tunnel lining cracks, the bearing capacity of the lining structure varies, and the stress distribution law varies as well, which will lead to crack development and new cracks, resulting in reinforcement of weak points. The research results show that through the combination of qualitative safety evaluation and quantitative theoretical calculation, the safety of the lining structure with cracks can be scientifically evaluated.