In this work, Al3Zr/A356 particle-reinforced aluminum matrix composites with 3% particle content were successfully prepared by in situ reaction. The effects of different welding parameters on the microstructure, microhardness and corrosion performance have been contrasted by controlled variables. The result shows when the pulse frequency is 15 kHz and the pulse peak current is 200 A, the welded seam is well-formed and the reinforcements are uniformly dispersed, which makes the hardness of the weld increase by 35% compared with the base metal. The electrochemical test combined with soak corrosion test exhibiting the corrosion mechanism is mainly pitting corrosion, supplemented by the comprehensive effect of stress corrosion and electrochemical corrosion. In addition, the corrosion mechanism of the welded joint of the composite was modeled according to the experimental results.