Silicone has been used as defoamer for jet dyeing, which has been reported in many literatures. In the old dyeing process, dimethyl polysiloxane defoamer is generally used, which can achieve satisfactory defoamer effect and ensure uniform dyeing. However, the new dyeing process uses high temperature and high pressure machinery, in which the dyed object is moved by the jet of dyeing liquid and dyed at the same time. Although the generated foam can be defoamed by ordinary silicone defoamer, under high temperature and high pressure, ordinary silicone defoamer will produce film-like precipitation, causing spots on the dyed object. The application of block polymer can overcome the above shortcomings, because these defoaming agents can be dissolved in cold water but not in hot water, so they can play a defoaming role. However, the defoaming effect of only using this polymer defoamer is not ideal. If a certain amount of atomized silica is added to the polymer, satisfactory defoaming effect can be obtained and evenly dyed fabric can be obtained. Used for defoaming in high temperature dyeing and fermentation of polyester fabric. In addition, it can also be used for defoaming of diethanolamine desulfurization system and various oil agents, cutting fluids, non-freezing liquids, water-based inks and other systems, and it is also suitable for defoaming of uncured resin after photosensitive resin plate making in printing industry. It is a representative defoamer in silicone with excellent performance and wide application.