With the continuous improvement of construction technology, prefabricated buildings have gradually become the mainstream. In order to improve the efficiency of on-site assembly construction and the performance of joint connection, a new type of spliced outer sleeve beam-column joint is designed and constructed. The three-dimensional solid model of the joint is established by ABAQUS, and cyclic behavior of the joint is simulated using finite element nonlinear analysis. The failure mechanism, hysteretic curve, viscous damping coefficient, the energy dissipation coefficient and stiffness degradation of the joint are analyzed. Based on the ideas of component method and superposition principle, a simplified method is proposed for calculating the initial stiffness and flexural capacity of spliced outer sleeve beam-column joints with U-shaped steel plates. The differences between numerical simulation and theoretical calculation results are compared. The initial stiffness and flexural capacity of the joint predicted by the theoretical formula are in good agreement with the numerical simulation results. The results show that the hysteretic curve of the joint is full, the stiffness degradation is stable, and the joint has good ductility and energy dissipation capacity. This new type of joint can provide some reference for practical engineering of fabricated structures.