Abstract: In order to study the application feasibility of the nodular cast iron-reinforced concrete composite liner slab as the tunnel lining structure, a three-dimensional finite element analysis method is used to simulate the loading environment of the test, and analyze the mechanical characteristics of the composite liner slab under loading.The analysis results show that when the concrete component reaches the ultimate state of compression failure, the composite liner slab can withstand the vertical pressure of 2.22 MPa and the horizontal pressure of 1.11 MPa, the maximum deformation occurs at the arch crown with the value of 6.63 mm; when the nodular cast iron component reaches the ultimate state of compression failure, the composite liner slab can withstand the vertical pressure of 11.48 MPa and the horizontal pressure of 5.74 MPa, the maximum deformation occurs at the arch crown with the value of 33.16 mm; under the effect of the nodular cast iron liner slab ring, the composite liner slab's ability to withstand the surrounding rock pressure and anti-deformation capacity are increased by 5 times compared with that of concrete liner slab under compression failure, which fully reflects the advantages of high strength and high ductility of the nodular cast iron.