Objective To investigate the anti-corrosion performance of EB/ epoxy-silicone composite coatings on Q235 mild steel in sodium chloride medium. Methods The epoxy-silicone composite coatings was prepared by the anti-corrosion pigment of EB, fillers and additives adding proportionally and sanding dispersion, mass fraction of it was 0.5%, 1.0%, 1.5%. Q235 mild steel was handled by sandpapering to remove the oil, and the coatings were prepared by spraying method. SEM tests were carried out to observe dispersed state of different quantity of EB in the epoxy-silicone composite coatings. X - ray diffraction was indicated that phase of the coatings after immersing, and the anti-corrosion properties were studied by means of open circuit potential and electrochemical impedance spectroscopy. Results When the content of EB was 1.0% in EB/ epoxy-silicone composite coatings, the particles were dispersed and the uniform dense passive oxide film were promoted. The microporous resistance value (Rpo=3.89×106 Ω?cm2) on the surface of coatings was higher after soaked, which exhibited excellent electrical chemical properties. When the content of EB was 0.5%, the particles were dispersed relatively sparse, and the impedance values and fitting resistance values of the coatings decreased. When the content of EB was 1.5%, the impedance values and fitting resistance values of the coatings were less, and the corrosion rate continued to accelerate. Conclusion the coatings with 1.0% EB were uniformly dispersed and density, which had the best anti-corrosion performance on Q235 mild steel in NaCl (3.5wt%) solution.