This series of defoamers is a new type of high-carbon alcohol polyether ester defoamer specially developed by our company for the cement concrete admixture industry, especially polycarboxylic acid water reducer. It is a new non-silicon product used to eliminate Hazardous foam of uneven size has a good effect, making the foam system more stable, and at the same time, it can balance the beneficial air bubbles generated by the air entrainer (without reducing its own strength). After testing in the concrete industry and feedback from field applications, the addition of this series of defoamers to the concrete system can improve the pore structure quality of the concrete, control the air content, and resist physical properties such as compressive strength, coagulation strength, and slump strength. The index has no effect, and concrete has good performance durability, and it is a defoamer product with excellent comprehensive properties. This series of defoamer does not demulsify, does not bleach oil, and has excellent alkali resistance. It also has the advantages of fast defoaming speed and long-term foam suppression.