Abstract: To address the difficulty in calculating dynamic reserves caused by abnormal pressure drop curves in a lithological low-permeability gas reservoir in Xihu Sag, East China Sea, this research investigates dynamic reserve calculation methods. Firstly, based on the characteristics of the pressure measurement data points in the gas reservoir, the causes of the abnormal pressure drop curve were analyzed. Then, well testing model simulation method, the intermediate data line extrapolation method, and the pressure measurement point method in the later stage of gas reservoir development were used to correct the pressure drop curve. Comparative analysis revealed that using intermediate data line extrapolation method to correct the pressure drop curve of the gas reservoir is more appropriate and the calculated dynamic reserves are more reliable. By analyzing the applicability of three methods, it has been clarified that the well testing model simulation method is suitable for early stage of gas reservoir development, the intermediate data linear extrapolation method is suitable for middle stage of gas reservoir development, and the pressure drop curve correction using the pressure measurement point method in late development is suitable for late stage of gas reservoir development. The specific usage application conditions of each method have been summarized, providing valuable reference for calculation of dynamic reserves in low-permeability gas reservoirs.