In this paper, a new type square steel tube column with inner sleeve fabricated connection is proposed. In the new connection, moving the column splicing up above beam-column node core area can provide space for high-strength bolt installation while keeps the continuity of joint panel zone. A series of finite element models were established by changing the thickness of the inner sleeve, the length of the inner sleeve, the spacing of the bolts, and the thickness of the end plate to analyze the hysteretic behavior, energy dissipation capacity and failure mode using nonlinear finite element method of ANSYS. The results show that the new connection has good ductility and energy dissipation, and different parameter has different effects on its mechanical properties. The provision of the reinforcing plate can improve the stress performance of the column splicing position, and increasing the thickness of the inner sleeve can improve the ultimate bearing capacity and energy consuming capacity. When the larger thickness of the inner sleeve is used, the ultimate bearing capacity and energy dissipation capacity of connection will be improved, especially the inner sleeve larger than the thickness of the column wall by 2 mm will work best. Appropriately increasing the distance between the split bolts can improve the mechanical performance of the connection. While the length of the inner sleeve increase, the initial stiffness, ductility and energy dissipation capacity of the connection reduced, so the length of the inner sleeve should be smaller when the structural requirements are met. While the thickness of end plate increase properly, the mechanical behavior and ductility and energy dissipation capacity of the connection will be improved obviously, but it is not economical when the end plate is too thick. The research conclusions can provide basic research data for design and application of the new type square steel tube with inner sleeve fabricated connection.