To address the inaccuracy of the Thornhill-Craver method in predicting gas-lift valve flow rates,research on gas-lift valve flow was conducted using air as the medium on a gas-lift valve test platform. Experiments were carried out on gas-lift valves with orifice sizes of 2.8, 3.2, 4.8 and 6.4 mm, resulting in a functional relationship between valve stem travel and flow coefficient, as well as critical pressure ratio for different orifice sizes. By considering the dynamic changes in surface pressure of the valve ball under operating conditions and introducing the degree of valve opening, the method for solving the valve stem stroke was optimized. A model for the flow area of the gas-lift valve was developed, and a new method for calculating the flow area was derived using known parameters. Based on experimental and theoretical analysis, a new model for predicting the flow rate of gas-lift valves was established. The research results indicate that the new model accurately predicts the flow rates of gas-lift valves for different orifice sizes and under various working conditions, with an average relative error of 3.34%, which is a significant improvement over the Thornhill-Craver method. This is of great importance for determining the working state of gas-lift valves downhole and for improving the precision of gas-lift design.