It is of great significance to accurately predict the sulfur deposition laws and location in wellbore of high sulfur gas wells. It can avoid pipeline blockage, corrosion perforation and other factors affecting gas well production. The mechanism of sulphur deposition is deeply studied. Based on the experiment of elemental sulfur solubility in Yuanba gas field, the prediction model of sulfur solubility is established. Based on the instantaneous heat conduction, the law of energy conservation and the theory of multiphase flow, the mathematical models of temperature and pressure in ultra-deep and high sulfur gas wells are established, and the multi-field coupling solution is carried out to obtain the prediction model of sulfur deposition in ultra-deep and high sulphur gas wellbore, an example of Yuanba gas well is analyzed. The results show that the higher temperature and pressure in wellbore, the greater the solubility of elemental sulfur, It is high calculate precision of the model of temperature and pressure in wellbore, the pressure error is less than 1% and the temperature error is less than 5%. the solubility of elemental sulfur decreases nonlinearly in the wellbore, with the largest bottom hole and the smallest wellhead. The research results will be used not only to predict the distribution of sulfur solubility in wellbore and sulfur precipitation section, but also to calculate the pressure of multiphase flow in the same type of gas wellbore, and lay the foundation for safe and stable production of gas wells.