This paper analyzes the action mechanism of the solvents.It is concluded that the heap leaching process is a dynamic one with multiphase chemical reactions in which the leaching-rate of target metals is dependent on the rate of the chemical dissolution as well as the diffusion of the reactants and resultants.Based on the theory of dynamic diffusion in multiphase reactions,the description in quantity of the metal recovery in heap leaching through the chemical solvents is given.The Dual Non-stability Seepage Model of the solvents in the porous media is derived under the assumption that the fissured rock mass is a similar continuous medium and the fluid flow in the whole rock mass obeys Darcy's law.