THEIC three silicate chloride ethyl was synthesized by using tri (2-hydroxyethyl) isocyanurate (THEIC),silicon tetrachloride and ethylene oxide as raw materials.The effects of solvent, reaction temperature and amount ratio of substance on product yield was discussed.The optimal conditions were selected as follows:n(silicon tetrachloride)﹕n(ethylene oxide)﹕n(THEIC)﹕n(ethylene oxide) was 3﹕6﹕1﹕3.3;Silicon tetrachloride was first reacted with ethylene oxide for 1h at 25℃,and then THEIC was added at 80℃ reaction for 8h,finally ethylene oxide was added at 40℃ reaction for 3h;The product was purified and the yield of product was 94.3%.The structure and properties of products was characterized by using FTIR,1H-NMR,DTA and limiting oxygen index techniques;The application experiments showed that the product contained silicon,nitrogen,chlorine three flame elements and had a good synergistic flame retardant synergism,it can be applied to polyvinyl chloride, polyurethane,epoxy resin and unsaturated resin polymer materials.