A new modified silicone oil with long carbon chain and alkoxy group(PHV)is synthesized using hydrosiloxane (PHMS)，hexadecene (HDE) and vinyltriethoxysilane (VTES) as raw materials by hydrosilylation.. The chemical structure of PHV was characterized by means of Fourier transform infrared spectroscopy (FT-IR). Using the gamma-(epoxy propyl ether 2,3-) propyl trimethoxy silane (KH-560) amino-modified nano-silica Sol and PHV for fabric processing, preparation of waterproof coating. micro topography of the coating membrane were observed by scanning electron microscopy (SEM), and corresponding application performance of the fabric were investigated by the static contact angle measurement instrument, whiteness meter and softness tester, respectivel. Results showed that many micro-nano scale tubercles were coated on the surface of the finished cotton fabrics. With increase of the amount of PHV, softness of the fabric reduced, and whiteness did not change significantly. As expected, fabrics have good waterproof performance and the highest angle on water surface can reach 142.1 ?