Abstract: Dynamic evaluation on fault seal integrity is a bottleneck in the underground gas storage construction, operationand management, because fault seal integrity directly affects the reliability and economy of underground gas storage'soperation. In this paper, taking the Banzhongbei Gas Storage as an example, a systematic fault seal integrity evaluation isgiven by integrating qualitative and quantitative methods, and the evaluation method based on multiple regression of naturalgamma is established as well. Moreover, the permeability and clay content diagram and the fault seal integrity evaluationand ranking table given in this paper provide a reference for the fault seal integrity evaluation of other gas storages. It isrecommended to deploy appropriate monitoring wells in the external reservoirs of existing gas storages to achieve longtermdynamic monitoring of faults in the production process, and take this as a major method for the gas storage reservoirintegrity management.