In order to investigate the behavior of the composite joints which used the T?stub connector under low frequency cyclic loading, the finite element software ABAQUS was used to analyze six specimens: concrete-filled steel square tubular column and steel beam composite joint with T?stub based on the experiment. The 3D nonlinear finite element analysis was about the beam-end under monotonic loading. By simulating square steel tubular, H?shaped steel beam, concrete, T?stub and high-strength bolt with four-node and eight-node solid elements; dividing mesh regularly and setting 96 normal contacts and 32 bonding contacts for contact part of joint region; carrying out the pretension force of high-strength bolt with the step loading method; the simulative results such as failure mode of joint region, flexural capacity and P?Δcurve agreed well with the experimental data. The stress distribution law of joint region analysis showed that increased thickness of steel tube or flange of T?stub would improve the capacity of the joints.