Abstract: The Xiazhuang uranium ore field in northern Guangdong is characterized by five sets of approximately equidistant NWW-trending diabase dikes, which are closely related to uranium mineralization. To determine the genesis of diabase and its relationship with uranium mineralization..(Methods) This study systematically investigates the diagenetic age, genesis of diabase, and its controlling mechanisms on uranium mineralization through geochemical analysis of diabase, apatite U-Pb geochronology, and H-O isotopic analysis of ore-forming quartz, combined with regional tectonic background. (Results) Results indicate that: (1) The diabase was formed during two magmatic events (200–180 Ma and 150–140 Ma), corresponding to the Early Jurassic and Late Jurassic, respectively.(2) The diabase is enriched in large-ion lithophile elements (LILEs) and highly incompatible elements. The chondrite-normalized rare earth element (REE) patterns exhibit right-leaning trends and no significant Eu or Ce anomalies, indicating an intraplate basalt affinity derived from mantle partial melting with metasomatism by subduction-related fluids.(4) The early-stage diabase (200–180 Ma) serving as favorable host rocks for uranium mineralization. The deep-seated faults associated with diabase emplacement provided pathways for ore-forming fluids, and the intersections between faults and diabase facilitated the formation of vein-type uranium deposits with crust-mantle hybrid fluids.The late-stage diabase (150–140 Ma) not only inherited the role of the early-stage diabase but also contributed mantle-derived fluids and mineralizing agents (ΣCO₂) during the 138–122 Ma uranium mineralization stage, promoting the formation of fractured alteration-type uranium deposits dominated by mantle-derived fluids.