Silica(SiO2) sol was prepared by sol-gel method using tetraethyl orthosilicate as the precursor. And then modified SiO2 sol(VTEO/SiO2) was obtained through modified SiO2 by triethoxyvinylsilane(VTEO). At the same time, polyaniline(PANI) which doped with phosphoric acid grafted silica composite particles(PANI/SiO2) were prepared. Subsequently, the PANI/SiO2-VTEO/SiO2 composite coating was formed on the surface of Q235 steel by coating the mixture of PANI/SiO2 and VTEO/SiO2. The chemical structure was characterized by Fourier transform infrared spectroscopy (FTIR). The composite coatings were observed by scanning electron microscope (SEM). Hydrophobicity of composite coatings was tested by contact angle instrument. The anticorrosion properties of PANI/SiO2-VTEO/SiO2 composite coatings were tested by electrochemical impedance spectroscopy (EIS), open-circuit potential (OCP) and potentiodynamic polarization. The results indicated that the water contact angle of composite coatings was 150°which showed excellent hydrophobicity. The impedance (5.5×106 Ω) and corrosion potential(-0.2 V) were higher, and the corrosion current density(1.18×10-8 A/cm2) was lower. The corrosion rate was only 0.0001 mm/a. The composite coatings showed excellent anticorrosion performance.