Generally, the tunnel-type anchorage in the suspension bridge has a strong capacity to resist the uplift load due to the appearance of the wedge. In this study, two failure modes, i.e. friction damage on the anchor interface and the surrounding rock rupture owing to lateral extrusion, are investigated based on the assumption of homogeneous surrounding rock and Mohr-Coulomb strength criterion. According to the distribution of the force on interface between anchors and rock, the equilibrium conditions are established to further analyze the change of stress on rupture surface within the surrounding rocks. Besides, the wedge-effect coefficients of the tunnel-type anchorage with respect to two failure modes are derived, comparing with the pull-out capacity of the anchorage with constant section. Subsequently, the formulations about the pull-out bearing capacity of tunnel-type anchorage are obtained under these two failure modes. Research results show that the wedge-effect on the pull-out bearing capacity of the tunnel-type anchorage has obvious regularities for different classes of surrounding rock. Finally, the calculated results by the proposed procedure are compared with measured values of the built tunnel-type anchorage. It is shown that the proposed procedure is reasonable to consider the wedge-effect for the bearing capacity of the tunnel-type anchorage.