The Jinling skarn-type iron deposit, located in the Zibo area of the northern West Shandong Block, exhibits close genetic relationships with the Jinling high-Mg diorite intrusion. Through petrographic observations of diorite intrusions and skarns in the mining area, this study identifies three distinct types of apatite: magmatic Ap1 in diorite, early hydrothermal Ap2 in skarn, and late hydrothermal Ap3. Geochemical investigations of these apatite generations provide critical constraints on the evolution of ore-forming fluids and the controlling mechanisms of iron mineralization. The diorite-hosted Ap1 shows elevated Cl content, while the development of hydrous minerals (e.g., amphibole and biotite) indicates a water- and Cl-rich magmatic system. Such magma generated iron-enriched fluids through intense hydrothermal exsolution under decompression conditions, establishing the foundation for iron enrichment. Hydrothermal Ap2 displays higher ⁸⁷Sr/⁸⁶Sr ratios compared to Ap1, with values approaching those of Ordovician gypsum-bearing carbonate strata, suggesting evaporite-derived materials were incorporated into the mineralization system through fluid-wallrock interactions. From Ap1 to Ap2, the Eu anomaly transitions from negative to positive values, indicating that carbonate assimilation progressively increased oxygen fugacity in the hydrothermal system. This promoted oxidation of Fe²⁺ to Fe³⁺ and subsequent magnetite precipitation. The gradual depletion of Fe, Mn, and rare earth elements from Ap2 to Ap3 reflects significant consumption of these elements during late-stage fluid evolution, coinciding decrease and progressive mineralization processes.