［Objective］ To address the insufficient long-term protective performance of waterborne anticorrosive coatings，composite fillers with excellent dispersibility and dual shielding-passivation anticorrosive capabilities were prepared. This study aimed to clarify the effects of keypreparation and formulation parameters on coating performance，thereby providing support for the development of high-performance waterborne anticorrosive coatings.［Methods］Polyaniline-mica iron oxide（PANI-MIO）composite fillers were prepared via in-situ polymerization of aniline（ANI）to form polyaniline（PANI） on the surface of mica iron oxide（MIO）. Their successful preparation was characterized by FT-IR and SEM. The fillers were dispersed in waterborne epoxy resin to form coatings，and the effects of the ANI/MIO feeding ratio and filler content on the dispersibility of PANI-MIO，as well as the mechanical and anticorrosive properties of the coatings，were systematicallyinvestigated.［Results］ PANI-MIO with different ANI/MIO feeding ratios maintained uniform dispersion in the coatings，but agglomeration occurred when the filler content was ≥15%. PANI-MIOslightly improved the coating hardness without affecting its impact resistance and cross-cut adhesion.The coating exhibited optimal anticorrosive performance when the ANI/MIO feeding ratio was 0. 1∶1 and the filler content was 15%. After immersion in 3. 5%NaCl solution for 40 days，its |Z|_{0. 1 Hz} remained above 10⁹ Ω·cm²，the intact coating showed non-corrosion after 3 000 h in the neutral salt spray test， and only slight local corrosion appeared at the scratch after 720 h in the scratch salt spray test. Incontrast，the |Z|_{0. 1 Hz} of the pure resin coating decreased to 10^{7. 5} Ω ·cm² in the same period，with blistering and pitting occurring after 600 h in the salt spray test，and obvious corrosion diffusion at the scratch after 240 h.［Conclusion］The PANI-MIO composite filler enhances anticorrosive performance through the synergistic effect of“MIO shielding + PANI passivation”. The optimal combination is an ANI/MIO feeding ratio of 0. 1∶1 and a filler content of 15%. This filler can balance the dispersionstability of the coating and its comprehensive mechanical-anticorrosive performance，providing afeasible solution for the upgrading of waterborne coatings in the industrial heavy anticorrosive field.