The formation of natural gas hydrates seriously affects the production efficiency of gas wells. Obtaining the correct temperature and pressure profile along the wellbore of gas wells is a prerequisite for accurately predicting the location of hydrate formation and using downhole throttling technology. According to the numerical iterative transfer law of wellbore microelement state parameters, a multi-field and multi-phase coupling method is proposed. Based on the analysis of typical temperature and pressure models, considering the gas well velocity field and density field, a gas well multi-phase correction coefficient is introduced. Based on the judgment method of multi-phase flow pattern, the friction gradient equation of multi-phase flow is obtained, and the respective theoretical prediction equations are created for the temperature field, pressure field, density field, and velocity field. Thereby, a wellbore temperature and pressure field model with multi-field and multi-phase coupling is established. The model was applied to K1 and K2 gas wells, and the calculation results of the research model were compared with the PIPESIM simulation results and measured values. At the same time, the mean μ, variance σ, and the coefficient of variation Cm were evaluated, and the results show that the coefficient of variation of the calculation results of this research model is less than 15%, which indicates greater accuracy than the PIPESIM simulation results. These findings provide a theoretical basis for the design of wellbore structures and the use of downhole tools.