To improve the ignition and combustion performance of aluminum, complementary metal is introduced into it to form binary alloy like Al-Mg, Al-Ti, Al-Zr and Al-Li. This paper mainly investigated the preparation, characterization, ignition, and combustion characteristics of Al-Mg alloy powder. Melt atomization technique was used to produce the spherical Al-Mg alloy powder containing 20 % mass content of Mg composition. The crystalline structure, morphology, element distribution, and thermal performance were characterized by XRD, TEM, SEM, EDS, and TG-DSC. Results show that the Al-Mg alloy had intermetallic phases of Al(12)Mg(17)and Al3Mg2, uniform element distribution, and no dense oxide shell at the surface. The laser-induced ignition and combustion characteristics of Al-Mg alloy powder were investigated by microscopic high-speed cinematography, photoelectric detection, and infrared thermal imaging methods. It is testified that Al-Mg alloy powder took intermetallic phase decomposition, then followed the two-stage combustion mode, and demonstrated gaseous emission and multiple microexplosion behavior during combustion. The ignition delay and ignition temperature were measured at elevated laser ignition power density. It is found that the temperature rise rate had a significant effect on the ignition delay.