Abstract: The color metallographic examination method was used to analyze the fire melt marks on aluminum wires, the anode coating method was selected to color the microstructure of the fire melt marks on aluminum wires. The results show that the microstructure of the aluminum wire fire melt marks after coloration was bright in color, the grain boundaries were complete and clear. The grain size of the aluminum wire short circuit bead was narrow and columnar, with slender grains. The grain size of the secondary short circuit bead was coarse equiaxed grains. The grain size of the fire melt mark was coarse equiaxed grain, the internal dendrite structure of the grain was obvious. The pore shape of the primary short circuit bead was more regular than that of the secondary short circuit bead, there were no pores in the fire melt marks.