We carry out a laser melting experiment of magnesium alloy by using a Nd∶YAG solid-state laser with rated power of 3 kW. The microstructure, phase, hardness and corrosion resistance of the sample are characterized by metallographic microscope, scanning electron microscopy, energy spectrometer, Vickers microhardness tester, and electrochemical workstation. The results show that when the laser power is 2 kW and the laser scanning speed of 40 mm/s, the surface of the sample has no cracks and severe depression. The surface structure is the melted zone is equiaxed crystals, and the internal structure is radioactive dendrites. With the increase of the laser scanning speed, the equiaxed crystal size of the surface layer decreases, and the radioactive dendrites in the melted zone gradually become non-radioactive dendrites. After laser melting, the heat-affected zone is organized into the grain boundary of the matrix, and the boundary between the heat-affected zone and the substrate is irregular. The energy spectrometer and line scanning results show that the surface elements in the melted zone are burnt, resulting in the peak hardness of the melted zone appearing in the near-surface. With the increase of the scanning speed, the peak hardness shows a downward trend, after laser melting, the corrosion resistance of the melting zone increases.