A two-dimensional three-phase mathematical model of forest fires constructed by the method of averaging over the height of the forest fuel layer is considered. The gas phase in the model is described by gas dynamics equations with the k − ε turbulence model and the eddy breakup model to describe the rate of turbulent combustion and the rate of heat generation; the solid phase is described by a system of evolution equations for the change in the volume fractions of forest fuel and solid products of their pyrolysis with kinetic formulas for the rates of chemical reactions; and the disperse phase is described by the transfer equations for the mass and energy of solid burning particles in the wind field above the forest fuel layer. For the numerical implementation of the proposed model, a parallel software package is created. The results of calculations of the forest fire propagation with consideration of the basic physical-chemical processes and mechanisms typical of the real forest wildfire propagation are presented.