Artificial cavern-based compressed air energy storage (CAES) power stations are a focal point in deep underground energy storage research, and evaluating their site suitability is of great importance. Based on the principles of safety and economic efficiency, the factors influencing site selection for artificial cavern gas storage facilities are systematically analyzed. A site evaluation system comprising 12 indicators is established, and the analytic hierarchy process is employed to calculate their weights and determine their relative importance. The results show that stratum lithology, regional structural stability, rock mass quality grade, site availability, and rock mass distribution range are the five primary indicators, with the others being secondary. In addition, based on engineering practice and expert judgment, a clear and user-friendly method for site suitability evaluation is proposed. This method allows for the rapid assessment of a target site’s comprehensive suitability score through a table-based scoring approach. Finally, a CAES project in Northwest China serves as a case study for comparative site evaluation. The results indicate that the main site demonstrates significantly higher comprehensive suitability than the alternative site, aligning with expert opinions and indicating that it should be prioritized for development. These findings provide theoretical support and technical guidance for the scientific site selection of artificial cavern-based CAES facilities.