Stochastic methods of modeling slow–moving processes controlled by diffusion make it possible to analyze the order-disorder phase transitions. The features of the kinetics of these transformations can also be identified due to these methods. Most of the investigations were made for binary alloys, taking into account the interaction of atoms in the first two coordination spheres. There is evidence that in real alloys the influence of the interatomic potential trimming radius is significant. The computer simulation results from the process of isothermal annealing of a binary metal nanofilm by a vacancy mechanism at various temperatures and the extent of the interatomic potential are presented. It has been established that with an increase in the extent of interatomic interaction potential, effects similar to those of temperature disordering a ear.