Abstract: Driven by the destruction of the North China Craton, large-scale crust-mantle mixed magmatism and concomitant upwelling of deep-seated high-temperature heat sources collectively shaped the anomalously high geothermal background in its eastern margin—Shandong Province, where abundant geothermal resources are preserved. However, the regional geothermal field characteristics, the spatial distribution pattern of terrestrial heat flow, and the heat source-water source driving mechanisms and accumulation patterns remain poorly constrained. Tectonic analysis, measurements of rock thermal conductivity and radiogenic heat production, borehole temperature logging, and calculations of geothermal gradient as well as conductive and advective heat flow were integrated to systematically characterize the geothermal field and the spatial distribution of heat flow across Shandong. Several high-heat-flow zones were identified, including the Jiaodong Uplift, the Tanlu fault zone, Qiguang fault zone, Lanliao fault zone, the basin–range fault zones in the central-southern Shandong Uplift, and the buried hills within the Jiyang Depression of northwestern Shandong. On this basis, a complete causal chain—lithospheric thinning → mantle heat flow uplift → fault-controlled thermal conduit → shallow heat flow focusing—was established which, from a deep geodynamic perspective, reveals the transport mechanisms of deep-seated heat through deep-rooted faults and magmatic activity, and further elucidates the physical processes governing shallow crustal heat accumulation. The results demonstrate that lithospheric-scale active fault zones reaching the mantle provide preferential pathways for the upwelling of mantle-derived magmatic and thermal materials. The heat flow values in these zones are significantly higher than the regional background values of their respective tectonic units, forming high-heat-flow geothermal anomalies, in which the advective heat flow component accounts for 29% to 70% of the total heat flow, confirming that deep convective heat upwelling is the dominant heat source for shallow high-heat-flow anomalies. At the shallow level, heat accumulation is governed by dual physical mechanisms: the thermal refraction effect caused by the high thermal conductivity of hard rocks in buried hill uplift zones—i.e., the lateral focusing of heat flow lines by the high-conductivity basement, and heat flow upwelling driven by high pressure gradients and high temperature gradients of compaction water and acidic fluids in depression centers. This study further demonstrates that incorporating the advective-dominated heat flow component into regional heat flow mapping can more accurately highlight high-heat-flow geothermal anomaly zones, thereby providing high heat flow as a critical and direct line of evidence for optimizing geothermal exploration target selection.