In order to realize the brazing joint of high strength aluminum-steel, took 08Al steel and aluminum alloy for automobile were taken as the experimental object, and pure aluminum powder was selected as solder by filling powder to carry on the experimental study of dissimilar metal laser fusion brazing. Based on energy dispersive spectroscopy energy spectrum analysis and X-ray diffraction phase analysis, the main intermetallic compounds at the interface of the joint are FeAl, Fe2Al5 and Fe4Al13. The effect of adding brazing flux on the whole forming of the joint and the effect of laser offset on the morphology and mechanical properties of the joint were studied. The results show that the addition of the bonding agent improves the joint forming defect and the wettability of the toe area. When the laser offset is 0.8mm~1.6mm, an effective fusion welding joint is formed. With the increase of laser offset, the wetting angle of the joint increases from 35° to 54°, while the thickness of intermetallic compounds in the reaction layer decreases gradually, and the tensile properties of the reaction layer increase at first and then decrease. When the laser offset is 0.8mm, the wetting angle of the joint is 38°, the thickness of the intermetallic compound in the reaction layer is 8μm, and the average mechanical resistance is 210N/mm, which has high engineering application value. The wetting angle of the weld, the width of the joint and the thickness of the intermetallic compound in the reaction layer determine the mechanical resistance level of the joint. The research will provide technical support and important guidance for ensuring the quality of laser welding of the body.