Abstract: 5052 aluminum alloy and 304 stainless steel arc welding brazing butt joints were successfully obtained by adjusting the welding current. Scanning electron microscope（SEM） was used to observe and analyze the microstructure of the aluminum/steel joints, and the effect of welding current on the interfacial morphology and mechanical properties of the joints was studied. The study shows that under the optimal welding current of 85 A, dense intermetallic compound layer is formed on the interface of the joint at the steel side, and the average thickness is 7.97 μm. It is determined by energy spectrometer（EDS） analysis that the interface reaction product is η-Fe2Al5and θ-Fe4Al13phases. Under tensile load, the tensile strength of the joint obtained at 85 A reaches 180.84 MPa, about 86% of the tensile strength of the aluminum alloy.The fracture path is located at the aluminum alloy weld near the fusion zone, and the fracture mode is a composite fracture dominated by ductile fracture.