Shield method is widely used in tunnel construction due to its high construction speed, high economic efficiency and good safety characteristics, and the application of communication channels will also become increasingly widespread. However, the research for small-diameter shield tunnel stiffness efficiency is relatively limited. Based on a shield method contact channel project in Tianjin, with ABAQUS to establish a variety of tunnel and segment numerical calculation model, study the size of small diameter tunnel stiffness efficiency and influencing factors. The study found that: (1) The stiffness efficiency of the contact channel is not different from that of ordinary tunnel, the longitudinal stiffness efficiency is around 0.07, the transverse stiffness efficiency is between 0.5 and 0.6, the transverse stiffness improvement has a positive relationship on the longitudinal stiffness; (2) The segment assembly method has little influence on the efficiency of longitudinal stiffness, and extremely asymmetric deformation under the joint assembly; (3) The tension of the bolt, which has some influence on the efficiency of the longitudinal stiffness, but has little influence on the efficiency of transverse stiffness.