A long time ago, it was found that water droplets always keep spherical rolling shape on lotus leaves. Dust and dirt are easily taken away by water drops, so as to achieve the effect of automatic cleaning. This phenomenon is called "lotus leaf effect". Later, scientists developed super hydrophobic materials based on the principle of "lotus leaf effect". The surface with static water contact angle greater than 150 °and rolling angle less than 10 °is called super hydrophobic surface. Super hydrophobic materials generally have nano composite structure and low surface energy chemicals at the same time. Therefore, super hydrophobic surfaces have excellent properties such as self-cleaning, oil-water separation, corrosion resistance, anti icing and anti fog.