The contacting and spreading characteristics of droplet on hydrophobic solid surface were studied.The impact and spreading process of droplet on the hydrophobic surface was studied by using the injection method to make droplet falling from the same height,and impacting and diffused on the Titanium alloy surface.Contact diameter and contact angle between droplet and surface were measured with high speed camera and contact angle measuring instrument.The result indicates that the contact between droplet and substrate surface includes impacting process and diffusion process.During impacting process on hydrophobic surface,a larger volume drop will get a faster average contacting speed on the substrate surface.Smaller volume and surface tension of droplet will enhance the contacting speed of droplet on the substrate surface in diffusion process.However,the effect of surface tension on contacting characteristics becomes weak as the increasing of hydrophobicity of the surface.