The accuracy of the comprehensive compression coefficient of the reservoir has an important impact on the analysis of pressure drop characteristics, reserve calculation, production capacity evaluation, and development method selection of abnormally high pressured gas reservoirs. For the exploitation of abnormally high pressured carbonat gas reservoirs, the influence of comprehensive elastic expansion energy of reservoirs other than gas cannot be ignored due to the development of dissolution pores and caves in the reservoir. At present, a constant comprehensive compression coefficient is commonly used in the interpretation of unstable well test data and prediction of dynamic reserves in normal pressure gas reservoirs. In fact, the comprehensive compression coefficient of reservoirs under different net stresses is variable and has stress sensitivity. In this paper, the core pore volume compression coefficient of X2 gas reservoir in Sichuan Basin is tested under the condition of high temperature and abnormal high pressure formation, and the difference of reservoir comprehensive compression coefficient under different water saturation is compared. The analysis results show that there is a significant numerical difference in the comprehensive compression coefficient of the reservoir under different net stress environments. In the evaluation of dynamic reserves and productivity of abnormal high pressured gas reservoirs, it is necessary to calculate the comprehensive compression coefficient of reservoirs under current pressure conditions. For edge and bottom water gas reservoirs with high water saturation, the influence of the compressibility of formation water on the comprehensive compression coefficient of the reservoir cannot be ignored.