Abstract: To study seismic performance of embedded and reinforced connection with cantilever beam, and the effect of change of component parameters on the seismic performance of connection. quasi-static analysis on the embedded and reinforced connection with cantilever beam was carried out, the calculation results can provide an optimized scheme for designing of this type of connection. By changing the number of bolts, the thickness and width of the extended flange, the length of the cantilever beam respectively, a series of finite element numerical calculation models of connections were set up. Failure mode, hysteretic behaviour, energy dissipation capacity, bearing capacity, stiffness degradation, and stress path are calculated and analyzed. Numerical calculation results of each series of connection are compared to analyze the effect of the number of bolts, the thickness and width of the extended flange, the length of the cantilever beam on mechanical properties of the connection. The analysis results show that the number of flange bolts has little effect on mechanical properties of the connection. Increasing the number of flange bolts on the basis of the connection designed by the equal strength design method has no obvious effect on the mechanical properties of the connection, while decreasing the number of flange bolts will reduce the integrity of the connection, and the connection will buckle in advance, but the bearing capacity and stiffness of the connection will not decrease significantly. Increasing the thickness of the extended flange and the width of the cantilever flange can significantly improve the energy dissipation capacity, bearing capacity and stiffness of the connection. However, when the thickness and width of the extended flange reach a certain degree, the energy dissipation capacity is not significantly improved, and the bearing capacity degrades rapidly. The stiffness degradation of the connection in the elastoplasticity stage is accelerated, and the failure of connection failure mode also changes, but the stress concentration is relieved. When the width of the extended flange is too wide, on the contrary, the energy consumption capacity of nodes begins to decrease. The length of the cantilever beam segment has a certain effect on the mechanical properties of the connection. Increasing the length of the cantilever beam can improve the hysteretic performance, bearing capacity and stiffness of the connection. On the whole, the effect on improvement is less obvious than that of changing the width and thickness of the extended flange. Because the thickness and width of the flange of the cantilever beam have a great effect on mechanical properties of the connection, it is recommended that the selection of the thickness and width of the extended flange are controlled by the section when the connection is designed, and the ratio of the cross-sectional area of the extended beam to the cross-sectional area of the flange of the middle beam section is recommended to be within the range of 1.10~1.29. Properly increasing the section of the extended flange of the cantilever beam can significantly improve the energy dissipation capacity, bearing capacity and stiffness of the connection. However, when the section of the extended flange of the cantilever beam is too large, the failure mode will change, and the mechanical properties will be slightly improved, but the degradation rate of the bearing capacity and stiffness of the connection will be accelerated.