Recently, the R&D department of Datian Chemical developed a new efficient silicone antifoam using a specially developed compound system, combined with silicone modified polyether and performance modifier. It is very suitable for foam control such as polyvinyl alcohol and other viscous system. By comparison test and customer evaluation results, the efficiency of this new product can reach several times and even more than ten times of the traditional antifoam agent. A very small amount of addition can achieve the desired effect of foam control, while greatly reducing the negative impact of the final product due to the large dosage. The antifoam is particularly suitable for the dissolution process of polyvinyl alcohol, the mixing process of suspension polymerization dispersant of polyvinyl chloride, and other high viscosity system.