In recent years, a new breakthrough in mineral exploration has been achieved in the Choushuigou area of Beishan, Gansu Province, where medium-sized and above VMS-type copper polymetallic deposits have been discovered. However, there is still controversy over their diagenesis and mineralization age, and a lack of precise dating basis has constrained the summary of mineralization laws and analysis of mineralization processes. Based on field geological surveys, the LA-ICP-MS zircon U-Pb dating was employed to conduct high-precision isotopic chronology on the ore-hosting phyllitic basaltic tuff. The U-Pb age of the zircon is 277.4±0.72 Ma, which is from the late Early Permian period. Therefore, it is classified as the Permian Jinta Formation rather than the previously classified Carboniferous Hongliuyuan Formation, indicating that the late Early Permian was also an important period for submarine volcanic-hydrothermal mineralization in the area. Comprehensive analysis demonstrates that the diagenesis and mineralization in the Choushuigou area occurred within an extensional rift setting during the Early Permian. The deposit exhibits definitive characteristics of the VMS-type copper polymetallic deposit, and the phyllitic basaltic tuff of the Permian Jinta Formation and VMS-type copper polymetallic deposits are key directions for breakthroughs in regional mineral exploration.