Abstract: To investigate the thermal protection effects of a heat sinking vest w ith phase-change material in high-temperature and high-humidity environment a nd the feasibility of numerical computation of heat transfer to the vest, based on the analysis of heat and mass transfer characteristic about the accouterments, a thermodynamic model was set up with the enthalpy method. The uniform energy equ ation was constructed for the whole domain, and the implicit difference equation was used in every node, the distribution of enthalpy was solved by numerical me thod. Simulation technique of the thermal system was established with the combin ation of human body thermal regulation model. It was used to analyze the accoute rments. A experiment was carried out to validate the final computer results, and the experimental and computer results were tallied well. The results indicate t hat using numerical method of phase-change material in heat transfer of vest is credible and appropriate.