Abstract: Deep carbonate karst geothermal reservoirs represent the main host of geothermal resources in coal mining areas. Owing to extensively developed karst-fracture systems and strong reservoir heterogeneity, a single geophysical method cannot accurately delineate stratigraphic architectures, fault structures and water-rich targets, which restricts efficient geothermal resource exploration and drilling site selection in coal mining areas. To address this technical challenge, this study takes Anju Coal Mine in Jining City, Shandong Province as the research object, and constructs an integrated detection system for water abundance evaluation of carbonate karst geothermal reservoirs, combining microtremor survey, wide-area electromagnetic method and high-precision method of electromagnetic frequency spectrum (MES). Through joint inversion of subsurface shear-wave velocity structure and electrical structure, the system supports systematic division of stratigraphic sequences and accurate interpretation of the location and occurrence of fault structures. Based on the comprehensive response characteristics of apparent resistivity and magnetic field components from the MES method, karst aquifer development intervals are identified and favorable water-rich zones are delineated, with corresponding proposals for geothermal drilling hole locations put forward. The results show that the roof elevation of the Ordovician Majiagou Formation limestone in the study area ranges from −1 100 m to −1 380 m, presenting a stepwise distribution with burial depth increasing gradually from east to west. Four fault structures, including F1 (Jining Fault) and F2 (Jining No.1 Branch Fault), are interpreted via comprehensive geophysical prospecting, among which F2 serves as the dominant water-conducting fault in the study area. Two favorable water-rich zones are delineated according to the anomalous response of the MES method. Accordingly, two geothermal drilling holes are optimized: ZK01 (the preferred hole with a recommended depth of 1 600 m) and ZK02 (the alternative hole with a recommended depth of 2 000 m).The combined detection mode of microtremor survey, wide-area electromagnetic method and MES method realizes technical complementarity among different approaches, improves the accuracy of stratigraphic characterization, structural interpretation and water abundance assessment for carbonate karst geothermal reservoirs, and provides a reliable technical basis for geothermal resource exploration and development.