The invention relates to a super plasticizer for a precast concrete component, and the super plasticizer is prepared by carrying out free radical copolymerization reaction on monomer a, monomer b, monomer c and monomer d in an aqueous medium, and adding alkali compound into the reaction product for neutralization, wherein the molar ratio among the monomer a, the monomer b, the monomer c and the monomer d is 1.0:(5.0-16.0):(1.0-4.0):(2.0-6.0). Compared with the traditional high efficiency water reducing agent, the admixture has the characteristics that (1) the early hydration of the cement is obviously improved, the compression strength of the concrete is improved, and especially the early strength is improved; (2) the problem of slump loss caused by polyether long side chain belt can be greatly improved, so that the slump loss resistance of the concrete is improved, and the requirements of pumping pipe pile concrete can be met; and (3) under the condition of low amount of admixture, the super plasticizer for the precast concrete component has remarkable dispersing performance, slump-retaining capability and enhancement effect, is especially remarkable in early enhancement effect, is very remarkable in the early enhancement effect at the room temperature or low temperature, and is stable in later strength increment, thus being conductive to accelerating the turnover of templates, and accelerating the construction progress.