Abstract: Epoxy resin (EP) is flammable and releases large amounts of heat and smoke during combustion, which limits its application in fields with high fire safety requirements. To improve the flame retardancy, smoke suppression and char-forming ability of EP, an illite-based Zn metal-organic hybrid flame retardant (IAZnMOF) was prepared by coordination of Zn²⁺ with 1,1′-ferrocenedicarboxylic acid (FDA) and aminotrimethylene phosphonic acid (ATMP) using illite as the carrier, and then introduced into EP to prepare IAZnMOF/EP composites. The structure and thermal stability of IAZnMOF were characterized by SEM, FTIR, XRD, XPS and TGA. The properties of the composites were evaluated by LOI, UL-94, cone calorimetry, TG-FTIR and mechanical property tests. The results show that Zn, P, N and Fe were introduced into the illite system, and the residual mass fraction of IAZnMOF at 800℃ is 91.64%. Compared with pure EP, the LOI of 2IAZnMOF/EP increases from 23.8% to 28.7%, and the UL-94 rating improves from NR to V-1. The peak heat release rate, peak smoke production rate, peak CO production rate and peak CO₂ production rate decrease by 73.5%, 67.0%, 78.4% and 76.1%, respectively, and the residual mass after combustion increases from 10.3% to 18.9%. Char residue and TG-FTIR results show that IAZnMOF promotes the formation of a compact intumescent char layer and suppresses the release of flammable and harmful volatile products. Its flame-retardant action is dominated by condensed-phase char formation and barrier effects, accompanied by gas-phase quenching by phosphorus-containing active species. As a result, the flame retardancy, smoke suppression and char-forming ability of EP are improved, while the mechanical properties of the composites are well maintained.