A finite element (FE) model was established for a concrete filled steel tube (CFST) composite column connected to an H-section steel beam joint with an outer sleeve. Considering the damage to concrete under cyclic loading and the Bauschinger effect in steel and referencing existing experimental data, the seismic behavior and failure mode of the joint were examined throughout the process. Furthermore, important parameters influencing the joint’s seismic performance were analyzed. The results indicated that the FE calculations were in good agreement with the experimental results, and the hysteretic curves of the joint were plump. The ductility coefficient was in the range of 3.17-4.19 and equivalent viscous damping coefficient was in the range of 0.211-0.326. The outer sleeve thickness significantly affected the failure mode of the joint. As the sleeve thickness increased, the deformation in the joint panel zone improved, and the failure section moved from the joint to the beam section. By reducing the width-to-thickness ratio and increasing the sleeve height, the hysteresis performance and stiffness of the joint were improved. The thickness and height of the reinforced ribs were positively correlated with the bearing capacity and stiffness of the joint. To ensure that the joint satisfies the stiffness requirements, the width-to-thickness ratio of the sleeve should not exceed 25, the height of the sleeve should not be less than 150% of the width of the sleeve, and the thickness of the reinforced rib should not be less than 50% of the width of the beam flange.