Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation.In the dynamic process of mass transfer,they are always neglected,but they are very important in the investigation of thermodynamic equilibrium.In this paper,the effect of water droplet in solvent sublation was discussed in detail,and the previous mathematical model of solvent subaltion was improved.Matlab 6.5 was used to simulate the process of water droplets,and the comparison between the previous hypothesis and the improvement in this paper showed the superiority,especially in the investigation of thermodynamic equilibrium. Moreover,the separation and concentration of the complex compound dithizone-Co(Ⅱ)from aqueous phase to n-octanol by solvent sublation also proved the improved mathematical model was reasonable. Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation. The dynamic process of mass transfer, they are always neglected, but they are very important in the investigation of thermodynamic equilibrium. In this paper, the effect of water droplet in solvent sublation was discussed in detail, and the previous mathematical model of solvent subaltion was improved. Matlab 6.5 was used to simulate the process of water droplets, and the comparison between the previous hypothesis and the improvement in this paper showed the superiority, especially in the investigation of thermodynamic equilibrium. Moreover, the separation and concentration of the complex compound dithizone-Co (II) from aqueous phase to n-octanol by solvent sublation also proved the improved mathematical model was reasonable.