In low-yield gas wells, liquid loading is a common problem due to energy loss and pressure drop along the wellbore, especially in the middle to late phases of development. Because liquid loading is inevitable, it is necessary to calculate how much liquid can be unloaded under the current yield. Inspired by dimensionless analysis, this paper explores the mechanism of liquid carryover at low gas-liquid ratios, analyzes the dynamics of gas-liquid two-phase flow, and then establishes a calculation model of liquid carrying capacity for low-yield gas wells. The effectiveness of our model was verified through the analysis on actual low-yield gas wells. The results show that our model can calculate the liquid carrying capacity at a high accuracy (>85%). The research results provide a good reference for normal production in the late phase of gas fields.