The invention belongs to the technical field of preparation of super-hydrophobic surfaces, and relates to a preparation method for a super-hydrophobic surface with a bionic micro-nano composite structure. From the angle of the super-hydrophobic surface, the super-hydrophobic surface is prepared by virtue of a mesoscale two-step etching method; etching treatment is carried out on a substrate surface twice; a micro-nano composite structure similar to a lotus leaf surface is constructed by utilizing a chemical or an electrochemical reaction etching substrate, and surface modification is carried out by virtue of a surface modifier to reduce surface free energy. The size of the micro-nano structure can be controlled by virtue of reaction time, a reaction temperature and concentration. A contact angle, on the surface of the micro-nano composite structure, of water drops is as high as 170 degrees while a rolling angle of the water drops is smaller than 5 degrees. According to electrochemical test results, corrosion resistance of a super-hydrophobic stainless steel sheet is 22 times that of common stainless steel. The method provided by the invention does not need special equipment, is low in cost, good in stability, excellent in super-hydrophobic property, good in corrosion resistance and can be applied to metal corrosion-resistant protection.