The Beishacheng intrusion is situated on the northern margin of the North China Craton. It comprises granite porphyry and porphyritic granite, which serve as the main host rocks for the Beishacheng Pb-Zn-Ag-Cu deposit. This paper presents a study on the Beishacheng intrusion, including LA-ICP-MS zircon U-Pb dating, petrographic geochemistry, zircon Lu-Hf isotopes, and mineral geochemistry analyses. The zircon U?Pb dating results suggest that the granite porphyry and porphyritic granite were formed in the late Early Permian. The granite porphyry was formed at 276.1 ± 0.64 Ma, while the porphyritic granite was formed at 274.9 ± 0.68 Ma. Both rocks are high in silica and alkali, and are peraluminous. Their rare-earth partition curves are right-leaning with moderate Eu negative anomalies (0.44 to 0.62). Both granite porphyry and porphyritic granite are enriched in LILEs such as Rb, Th, U and K, and are deficient in HFSEs such as Nb, Ti and P, representing different evolutionary stages of the same magmatic system. The εHf (t) values of the Beishacheng pluton range from ?7.37 to ?14.54, and the two-stage model age (T_DM2) ranges from 1763 to 2215 Ma, indicating that the Beishacheng intrusion originated from the partial melting of Paleoproterozoic crustal material. Mineral geochemical studies indicate that the oxygen fugacity (ΔFMQ) of the intrusion ranges from ?2.8 to 0.74. Additionally, biotite crystallized at temperatures ranging from 740 to 766℃ and pressures ranging from 2.80 to 4.41kbar. The water content of the Beishacheng intrusion range from 8.0% to 8.3%. The diagenetic connection between the Beishacheng intrusion and the Beishacheng deposit is unclear due to the low oxygen fugacity and early fluid dissolution of the Beishacheng intrusion, which are unfavorable for the accumulation of Pb, Zn and Cu.