The Dahutang tungsten polymetallic deposit is located in the western segment of the Jiuling-zhanggongshan uplift in the Jiangnan orogen. The zircon U-Pb geochronologic, geochemical and Nd-Hf isotopic stud_ies of the Yanshanian Dahutang ore-forming granite-porphyry were carried out in this paper. The LA-ICP-MS zircon U-Pb age of the Dahutang granite-porphyry is 146.01±0.78 Ma. The granite-porphyry is characterized by high content of silicon and alkalis and high differentiation index, which, along with the characteristics of the major and trace element, suggests that the granite might be highly differentiated S-type granite. The Rb/Sr and Rb/Nb ratios of the granites are significantly higher than those of the upper crust and eastern China's upper crust, indicating that the granite-porphyry originated from melting of high-maturity crustal components. The ratios of Nb/Ta and Zr/Hf are much lower than those of normal granite, and there is REE tetrad effect, suggesting a strong melt-fluid interaction at the late stage of magma evolution. Heterogeneous Hf isotopic composition [εHf(t) =-19.9～-5.3;t_DM2=1.54～2.46 Ga] demonstrates that the granite-porphyry was derived dominantly from a Precambrian crustal source of 1.9～1.6 Ga and part of basic rocks, with the involvement of small amounts of late Archean basement rocks of Yangtze craton (2.5 Ga). The A/CNK ratios of the granite-porphyry are all higher than 1.15, suggesting that the granite-porphyry is a syn-collisional (syn-orogenic) granite rather than a volcanic arc granite; the young granite-porphyry has the post-collisional (post-orogenic) characteristics in the tectonic environment discrimination diagrams. The tectonic setting evolution of the old granite-porphyry and the young granite-porphyry indicates that "the extrusion-extension cycle" lasted about 11Ma with the transition from extrusion to extension in this area. This extrusion-extension cycl of 11Ma provided sufficient required dynamic duration for the multiple rock-forming and ore-forming activities in this area, and also served as an important geological prerequisite for extensive mineralization.