Abstract: By using melting blend method,flame retardant methyl vinyl silicone rubber(MVMQ)/clay nanocomposites were prepared with magnesium hydroxide(MH)and microencapsulated red phosphorus (RP)as synergistic flame retardant additives,aero silica(SiO_2)as synergistic reinforcement filler.The morphologies of the flame retardant MVMQ/montmorillonite nanocomposites were characterized by environment scanning electron microscopy(ESEM),the interlayer spacing were determined by small-angle X-ray scattering(SAXS).In addition to mechanical measurements,the flame retardance and smoke suppression of silicone rubber/clay nannocomposites were studied by means of LOI,UL 94 vertical burning tests,TG,and ESEM analysis. Combined with the change of combustion performance.the flame retardance mechanism of MH/RWMVMQ/clay nanocomposite was deduced.