Abstract: Affected by the high temperature fluid in the formation during the production process of high temperature and pressure gas(HTHP) gas wells, the original balance of the wellbore temperature will be broken and the redistribution of the wellbore temperature will cause the annulus pressure to increase, which will threaten the safe service of the wellbore and the integrity of the wellbore. In order to accurately predict the temperature of the wellbore, based on mass, momentum, energy conservation, heat transfer theory and wellbore heat transfer theory, by considering the influence of gas Joule-Thomson effect, gas temperature,pressure, density and physical parameters, a wellbore temperature prediction model will be established. The fluid property parameters will be calculated according to different temperature pressures so as to improve the accuracy of the model calculation.