In large-scale concrete projects, the polycarboxylate superplasticizer is severely adsorbed by a small amount of soil in the raw material sand and gravel, which causes its performance to decline. Therefore, modification research aimed at improving the performance and mud resistance of polycarboxylate superplasticizer is a hot spot in the field of polycarboxylate superplasticizer. The synthesis of active macromonomer is an important part of the modification of polycarboxylate superplasticizer. This article introduces the common mechanisms in polymer polymerization and the catalysts used in different mechanisms and their research progress, and summarizes the advantages and disadvantages of different polymerization mechanisms in the synthesis of active macromonomer of polycarboxylate water-reducing agents, prospects for the research of catalysts used in different polymerization mechanisms.