This paper adopts the melt blending method for organic silicon resin/nano Al 2 O 3 and PF.The organic silicon resin in the blending resin cures and forms interpenetrating network structures to improve the heat resistance of PF plastics.TG, DSC and FESEM analysis characterize the changes in heat resistance of the blend-modified PF plastic.In addition, this article investigated the heat-resisting performance of resin composite, which is modified by nano Al 2 O 3 as a coupling agent.FT-IR is used to explore the changes.The modified nano Al 2 O 3 can improve the heat resistance of the composite materials effectively.When the temperature reaches 800 ℃ , the residual rate of modified nano Al 2 O 3 /silicone/PF composites is about 78.07%.