Abstract: In order to evaluate the effects of high temperature and high humidity environment on mine worker,the thermal insulation and evaporative resistance of high temperature mine uniform were measured with the applications of a sweating thermal manikin and an artificial environment chamber. In consideration of the influence of air velocity and human body movement,the dynamic thermal insulation and evaporative resistance of mine uniform were calculated and corrected. The related parameters and calculation method of Predicted Heat Strain( PHS) model were improved with the measured and corrected thermal insulation and evaporative resistance of mine uniform.Ba sed on the improved PHS model,heat physiological responses of miners were calculated and analyzed under a variety of hot and humid conditions. With human rectal temp erature and sweating amount collected as the major evaluation index of heat safety,the maximum exposed working time accepted by the miners under several hot and humi d conditions was analyzed and determined. The study results showed that under the environment condition that the temperature is below 28°C and the relative humidity is n ot over 90%,the maximum exposed working time accepted by the miners could be effectively increased with the air velocity speeded up in underground mine. When the air velocity is over 2 m 1 s in underground mine,variation degree of the maximum exposed working time accepted by the miners would be small.