In the production cycle of gas wells, with the decrease of production, the liquid carrying capacity of gas in the wellbore decreases, and the location of liquid accumulation gradually increases. When the amount of liquid accumulation in the wellbore is large, some gas wells will stop production, which seriously affects the development effect of the well area. Aiming at the production data of gas wells in a low-yield and low-efficiency well area, the critical liquid-carrying model theory is used to compare the prediction effects of different models, and the critical flow calculation method is modified to quantitatively judge the effusion situation. The oil-casing pressure difference method is used to predict the location of effusion and comprehensively judge the effusion situation. In this paper, a more suitable liquid loading prediction model for gas wells in low-yield and low-efficiency well areas is fitted, and the application of tubing-casing pressure difference method in the prediction of liquid loading position of gas wells in such well areas is introduced. The comparison and verification are carried out, which provides a more accurate guiding significance for the prediction of liquid loading in such well areas, and can ensure the scientific and efficient exploitation of gas wells.