To investigate the Early Cretaceous magmatic activity and tectonic evolution in the Xiaoqinggou mining area of Jilin Province, the authors conducted petrological, geochemical, and isotopic analyses of diorite rocks. The findings show that the zircons exhibit distinct magmatic growth zoning, confirming their magmatic origin. LA–ICP–MS zircon U–Pb dating yielded an age of 128.7±2.2 Ma, corresponding to Early Cretaceous. Geochemical data reveal that the diorite rocks are high and potassium but low in sodium, classifying them within the peraluminous, high-potassium calc-alkaline series. They are enriched in large ion lithophile elements (e.g., K, Ba and Rb) and depleted in high field strength elements (e.g., Nb, Ta and Ti). The δEu values range from 1.07 to 1.14, indicating weakly positive Eu anomalies. Regional comparisons and integrated studies suggest that the Xiaoqinggou diorite rocks formed in a volcanic island arc setting, associated with the westward subduction of the Paleo-Pacific plate beneath the Eurasian continent in an extensional tectonic environment. This study provides a theoretical basis for further exploration of the Xiaoqinggou deposit.