The work aims to study the effects of microstructure modification on hydrophobic material surface, and provide guidance for preparation of superhydrophobic surface. Based on finite element software, a wettability model in which water droplets modify different microstructures of hydrophobic surface was established. The effects of single rough structure and composite rough structure modified with hydrophobic materials on improving hydrophobicity were measured and analyzed using apparent contact angle of water droplets. Hydrophobic coatings of different roughness were prepared using silicon resin-doped particles and then cured. Actual contact angle was tested and compared with simulation results. After single rough structure was modified for the surface with water droplet contact angle of 100°, contact angle of water droplet on the surface increased to 133° as groove formed by microstructure obstructed air and prevented water droplet from spreading on the surface. Then the contact angle reached 168° after smaller microstructure was modified on the original microstructure, which was similar to superhydrophobic surface. The contact angle of water droplet increased as surface roughness increased in the actual experiment, which reached 162° as composite microstructure formed on the surface after curing of the hydrophobic coating containing two kinds of particles. The experimental data fitted well with the simulation result. Modifying microstructure on hydrophobic surface can significantly improve surface hydrophobicity., The surface will be superhydrophobic after composite structure is modified, which can be used for preparing superhydrophobic surface in actual engineering.