By using the finite element simulation method, a utility tunnel model has thus been established with joints taken into consideration, followed by an analysis of the seismic response characteristics of L-shaped and T-shaped socket joints under combinations of different lengths and extension lengths. The results show that the longer the extension lengths of the L-shaped socket joint, the less conducive it is to improving the seismic performance of the utility tunnel. Specifically, optimal seismic performance can be achieved when the length is 0.2 m and the extension length is 0.1 m. As for T-shaped socket joints, with an increase of the convex block length and the extension length, the horizontal relative displacement decreases, thus enhancing the seismic performance, while the shear stress increases accordingly. Based on a comprehensive comparison, it is found that an increase of the size of T-joints is more conducive to improving the stability of the utility tunnel.