Abstract: Using 1060 aluminum and SPCC nickel-plated steel as base materials, the effects of laser type, weld trajectory and outer diameter of spiral point on the welding performance of aluminum/steel dissimilar metals were studied based on the welding structure of aluminum on steel. The results show that compared with multi-mode laser and pulse laser, 14μm single-mode laser can realize effective welding between aluminum and steel, with concentrated welding heat, small weld heat affected zone and good bonding between aluminum and steel interface.The six-spot welding trajectory enables effective deep penetration welding of aluminum/steel（penetration ＞ 0.25mm）.The weld pool of the continuous arc welding trajectory is seriously depressed and there are cracks in the weld. The weld obtained by the six-spot trajectory has good appearance, stable penetration and no obvious cracks, and the shear force of the weld is higher than that of the arc welding trajectory. With the increase of outer diameter of spiral point,the weld penetration depth obtained by the six-spot trajectory increases, but the mechanical properties first increase and then decrease. When the outer diameter of spiral point is 3mm, the melting depth is 0.326mm, and the shear force and stripping force of the weld reach the maximum value. In summary, it can be seen that the multi-spot welding process under the single mode laser can realize the good connection of aluminum/steel dissimilar metal sheet.