Membranes are made by doping and modifying the Nafion117 with Nano-silica(SiO2). The penetration and the proton conductivity of composite membrane are studied through gas chromatograph and electrochemical workstation. With the help of cross-section spectrum, it shows that the SiO2 particles can penetrate the internal membrane and the weight percentage is greater than 0.1% after doping and modifying the membranes of Nafion117, so the SiO2 particles has a very good combination with the substrate. The membrane which is handled by Sol on 60°C has high proton conductivity and high water retention performance in high temperature. The permeability coefficient of membrane which is handled by Sol on 60°C and by the other ways are 4.07×10-4cm2/s and 8.13×10-4 cm2/s respectively. It shows that the permeability coefficient of ethanol membrane is reduced by half after the Nafion117 membrane is handled by Sol on 60°C.