Abstract: Flame retardant ethylene-vinyl acetate (EVA) composites were prepared by combination of microencapsulated intumescent flame retardants-ammonium polyphosphate (APP)-pentaerythritol (PER) and organically modified montmorillonite (OMMT). The microencapsulated APP (MCAPP)-microencapsulated PER (MCPER)-OMMT/EVA composites were further characterized through XRD and TEM, confirming OMMT sheets are well dispersed in the matrix as exfoliated or intercalated nanocomposite state. Limiting oxygen index (LOI), TGA, underwriters laboratories 94 vertical burning (UL-94), cone and smoke density test results indicate the synergistic flame retardancy effect between MCAPP-MCPER and OMMT in MCAPP-MCPER-OMMT/EVA composites. Replacing the same amount of MCAPP-MCPER with 3wt% OMMT could improve the LOI value of the MCAPP-MCPER-OMMT/EVA composites from 25.5vol% to 29.5vol%. The UL-94 rating increases from V-2 to V-0. The char residue of MCAPP-MCPER-OMMT/EVA composites is improved from 14.5wt% to 15.9wt% and the smoke density significantly decreases from 154.7 g/s to 97.5 g/s. Besides, the mechanical property of MCAPP-MCPER-OMMT/EVA composites was tested by universal testing machine and dynamic thermomechanical analysis (DMA), the result shows that the flame-retardant MCAPP-MCPER-OMMT/EVA composites has better mechanical properties.