The AZ31 magnesium alloy and TiB2 enhancement aluminum matrix composites are welded by a pulsed laser and the microstructures, the properties of corrosion resistance,hardness and so on for the welded joints are investigated. The effect of the addition of TiB2 interlayers on the performance of the welded joints is studied. The results show that, when the single point energy of the pulsed laser is 36.15 J, the parameters are defocusing, pulse frequency and welding speed sorted from the greatest to the least according to their influence degrees on the weld formation. Under the optimal welding parameters, there are equiaxed grains and no obvious defects in the weld zones of joints. There exist layered abundance zones on the top of the weld beams and Mg17Al12, AlMg, Al3Ti intermetallic compounds in the middle of the weld beams. As for the corrosion resistance rate, that of TiB2 enhancement aluminum matrix composite is the strongest, that of the weld microstructure is the next, and that of the AZ31 Mg alloy is the weakest.