The invention provides a high-efficiency water reducer, which relates to the technical field of concrete admixtures in building materials, including polyethylene glycol monomethyl ether, malein rosin, phthalic anhydride, sodium p-styrenesulfonate, concentrated sulfuric acid, and sodium hydroxide solution , vitamin c, vitamin e, vitamin b, azobisisoheptanonitrile, dimethyl azobisisobutyrate, ammonium persulfate, foaming agent, defoaming agent, ultrapure water. The present invention takes polyethylene glycol monomethyl ether and maleic rosin as main raw materials, vitamin C and vitamin E as reducing agents; azobisisoheptanonitrile, dimethyl azobisisobutyrate and ammonium persulfate as Initiator, adding modified silicone defoamer, the high-efficiency water reducer made of good stability, used in concrete, can increase its workability, and this water reducer can be mixed with other water reducers to make The process is simple, the cost is low, and the practicability is high.