Abstract: The application of 3D-printed materials in automobiles has increased to meet the demands of customization and rapid development of parts. It is unclear whether the spot welding performance of 3D-printed materials meets the demand during service of automobiles. Experimental methods were used to study the formation and mechanical properties of resistance spot welds of 3D printed maraging steel to DP600 dual-phase steel. Due to material properties and surface roughness differences between 3D-printed materials and traditional steel plate, there are differences in nugget growth and nugget profile compared with those of the traditional steel spot welds. The lap-shear strength of 3D-printed maraging steel/DP600 joint is higher than that of dual-phase steel joint, which meets the strength requirement. The printing orientation has influence on the joint’s performance. The surface roughness of the maraging steel with printing orientation of 45° is about three times of that of the steel with 90° printing orientation, which delays the nugget formation in the spot welding joint. Considering joint’s formation and mechanical properties, the maraging steel with printing orientation of 90°has better resistance spot welding performance