The existing models of evaporation of liquid propellant droplet under high pressure have been modified by the authors. A submodel of solution of surrounding dielectric gas in droplet was developed to investigate the effect of solubility on evaporation under high pressure. A modified R-K equation of gas state was used in the model. Using the model，the evaporation of propane droplet in a nitrogen environment was simulated. It was found that the evaporation time of droplet decreases with the increasing of pressure and environment temperature and that the droplet wi1l reach a supercritical state when the pressure is greater than a critical value. The solution of surrounding gas in droplet is very obvious under high pressure，and the higher the pressure，the greater the solubility. So it is important to take the effect of the solution into account in high pressure combustion of propellant.