6061 aluminum alloy with nickel-based self-melting alloy was alloyed by using YAG laser alloying method. The effects of process parameters on microstructure, composition, mechanical properties, and precipitates were investigated. The process of heat flow on the evolution of nitride precipitates in the alloyed zone were also investigated. Results show that the alloying zone increases wider and deeper as the current increase and the scanning speed decrease. From the alloyed surface to the substrate, the precipitated phase first appears as Al3N, followed by Al3Ni2 and AlNi until the AlNi is present of junction of the alloyed zone and the substrate. The hardness value gradually increases with depth and then decreases steeply to be close to the hardness of substrate. The hardness of the alloyed zone is up to 539 HV, which can be 6 times the hardness of the substrate.