By means of scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and optical contact angle measuring instruments, the microstructure, ingredient and hydrophobicity of dragonfly wing surface was investigated. Results show that dragonfly wing surface is covered with large number of papilla, leading to the composite contact between liquid droplet and dragonfly wing surface, which enhances the hydrophobicity of dragonfly wing surface. The waxy layer increases the hydrophobic capacity of dragonfly wing surface. Moreover, the hydrophobic equation of dragonfly wing surface was established through the Cassie model, and the multivariate coupling mechanism of dragonfly wing surface was analyzed. It is the conclusion that the hydrophobicity ascribes to co-coupling of the microstructure and ingredient of dragonfly wing surface.