Abstract: The micro-nano structure of Q235 steel was constructed,which can improve its hydrophobicity with shot peening and etching method. The shot peening and solution etching were used to prepare micro-nano structure on the surface of Q235 steel, and then modified with 12-hydroxystearic acid. The surface morphology of the sample was observed by SEM and its roughness was measured by laser confocal. The grain size of the sample surface was calculated by XRD analysis and Scherrer formula.The contact angle of the water droplet on the sample surface was measured by contact angle measuring instrument. The results show that after the shot peening-etching, the surface roughness of the sample increases, after 30 s shot peening, the roughness reaches 1.391 μm; the grain size keeps decreasing, after 40 s shot peening, reaching 1.12 nm; the surface water contact angle increases up to 114°. It is feasible to construct micro-nano structures on the Q235 steel surface to prepare a hydrophobic surface by shot peening and etching method.