Abstract: Objective The aim is to improve interfacial bonding strength and corrosion resistance of Al/steel dissimilar metal welded joints, and to explore mechanism of pulsed magnetic field on microstructure and properties of the joints during cold metal transfer (CMT) welding-brazing. Methods Pulsed magnetic field was introduced into CMT welding-brazing. ER4047F flux-cored wire was used as filler metal to butt 2 mm-thick 6061 aluminum alloy and Q235B steel. Macro morphology, microstructure, mechanical properties and corrosion properties of the joints with and without magnetic field were compared and analyzed. Results The results showed that pulsed magnetic field significantly improved wetting and spreading behavior of weld, resulting in full-formed joints with larger metallurgical bonding interfaces. Magnetic field did not change main composition of intermetallic compound (IMC) layer, but inhibited diffusion of Fe element and reduced thickness of brittle Fe-Al IMC layer. In addition, electromagnetic stirring made IMC layer wavy and refined grains, thus significantly increasing the interfacial bonding strength by 49.9% compared with that without magnetic field. According to electrochemical measurements, pulsed magnetic field suppressed galvanic corrosion by controlling thickness of IMC layer, and hindered the diffusion and erosion of corrosive medium along grain boundaries by grain refinement. Conclusion Pulsed magnetic field can effectively optimize microstructure and morphology of Al/steel CMT welded-brazed joints, enhance interfacial bonding strength and corrosion resistance, which provides a feasible control method for high-quality welding of Al/steel dissimilar materials.