The structure and phase transformation of the Al-Cr-Ni coating obtained by the diffusion interaction of the H20N80 + AD1 multilayer composite material during heat treatment are investigated in this paper. Investigations were carried out at 1150 °C with the heat treatment holding time of 1-50 hours. It is established that an increase in the heat treatment duration leads to the alignment of the coating chemical composition accompanied by increasing the concentration of nickel and decreasing the aluminum concentration. It is shown that the diffusion redistribution of Al in the coating during thermal exposure in the Al-Cr-Ni system is slower than in the binary Al-Ni system