In order to solve the difficulties in numerical simulation of elastic gaskets in shield tunnels and avoid the limitations of current gasket design methods based on experience and comparison, 3D model based on explicit FEM is introduced to simulate the compression of elastic gaskets. The simulation result is compared with the mechanical test result and factors which influence the mechanical property of elastic gaskets are analyzed. Conclusions drawn are as follows: 1) The explicit FEM adopted is effective; 2) The influences of rubber hardness and opening ratio on the gasket compression are analyzed, which shows that the harder the rubber and the smaller the opening, the harder the rubber gaskets and the more difficult the rubber gaskets can be compressed. 