Abstract: Compared with disk-buckle scaffold, combined shoring tower has smaller eccentricity, better mechanical performance and high construction efficiency. It is suitable for nuclear power construction projects with large structural changes. Under vertical loads, the failure of combined shoring tower mainly includes two types: the bending deformation of the vertical rod and the rotating deformation of the joint. Among them, the degree of joint rotation deformation is mainly related to its rotation stiffness. In this paper, the finite element models of combined shoring tower joints are established and validated by the full-scale model test. By considering the impact of sleeve length, socket length and cross section weakening on the rotational stiffness of the joint in the combined shoring tower, the structural recommendations are provided.