Polyether defoamer is a kind of defoamer widely used in recent years, and its defoaming property is good. The advantages of polyether defoamers are that they are nontoxic and convenient to use. The most important thing is that they have good antifoam performance, dispersibility, thermal stability and chemical stability, which ensure the stability of defoamers. The biggest drawback of such defoamer is the low efficiency of bubble breaking. That is to say, when the foam has been generated in the system, it is very difficult for polyether defoamer to remove the foam quickly. It also tells us that polyether defoamer should be added at the initial stage of the paint process, which can effectively inhibit the foam generation and give full play to the excellent antifoaming property of the defoamer. Organosilicon defoamer has the advantages of strong defoaming, low temperature requirement for the use environment, stable physical and chemical properties, and physiological inertia, which will not bring harm to human body. It can be used in both water-based coating system and non-water-based coating system. The disadvantage of organosilicon defoamer is that its preparation process is complex. If the control is not good, the defoamer effect will be affected. The defect of surface shrinkage due to its low surface tension.