In order to improve the seismic performance of steel frame welded connections, a new type connection with combined strengthened cover and hole weakened web was presented. Low-cyclic reversed loading tests and finite element analysis were carried out on four steel beam-to-column connections with different structural forms (standard form, cover-plate reinforced form, web-opening weakened form, and new form). The influence of local structural forms at beam end on the failure modes, hysteretic behavior, bearing capacity, stiffness degradation, ductility and energy dissipation capacity of the specimens were compared and discussed. The results show that, compared with the standard connection, the connection with local structural forms realizes the outward movement of plastic hinge from the connection zone, making the failure mode from the brittle failure of the connection weld to the plastic failure of the beam . Plastic deformation capacity and energy dissipation capacity are significantly improved as well. Plastic strain accumulation aggravates the local buckling of plates, resulting in gradual degradation of strength and stiffness, and the seismic performance is superior. In addition, under the premise that the bearing capacity and stiffness basically remain unchanged, the ductility and energy dissipation capacity of the new type connection increase by 20.0% and 27.9%, respectively, which verifies the feasibility of this connection. The finite element model, based on stress triaxiality damage criterion illustrated in this paper, can well predict the mechanical performance of various types of steel-frame-welded connections under cyclic loading.