Abstract: This study focuses on the Jinling skarn-type iron mine in Zibo, Luxi region, and applies advanced nanomineralogical techniques, including scanning electron microscopy (SEM), focused ion beam technology (FIB), and transmission electron microscopy (TEM). Through meticulous analysis, euhedral geometric wüstite (Fe_xO, x≤1) inclusions were identified within magnetite crystals. The measured lattice spacings of 4.87 Å and 4.21 Å precisely match the (003) and (012) crystal planes of wüstite, indicating a distinct mineralogical signature coexisting with magnetite. Our findings suggest that these wüstite inclusions originated in an early magmatic hydrothermal environment characterized by high temperatures exceeding 570℃ and extremely low oxygen fugacity levels (logfO₂ = FMQ-2.5-FMQ-4). This formation was primarily driven by the pyrolysis of siderite, with the resulting wüstite subsequently encapsulated by late-stage magnetite crystallization. The discovery of wüstite inclusions unveils a complex evolution of ore-forming fluids. Initially, the exsolution and boiling of Cl-rich magmatic fluids created a low oxygen fugacity condition, enabling the migration of Fe²⁺ in the form of chloride complexes. As the mineralization process advanced, the intrusion of sulfates (e.g., CaSO₄) from the Ordovician gypsum strata triggered redox reactions, significantly elevating the oxygen fugacity of the fluid. This chemical shift facilitated the oxidation of Fe²⁺ to Fe³⁺, leading to the precipitation of magnetite in association with sulfides. This research not only broadens the known occurrence environments of wüstite, demonstrating its formation potential in shallow hydrothermal systems under high-temperature, low-pressure, and low-oxygen-fugacity conditions, but also provides crucial mineralogical evidence for elucidating the metallogenic mechanisms of skarn-type iron deposits. Moreover, it offers novel insights into the iron ore mineralization processes in the Luxi region, contributing significantly to the broader field of economic geology.