Polycarboxylate superplasticizer (PCE) provides a new approach to improve the dispersity and workability of alkali-activated slag (AAS) cementitious materials. In this paper, the effects of PCE molecular structure and solubility on the dispersity, workability of AAS slurry, as well as the mechanism of PCE on AAS are reviewed. α-allyl-ω-hydroxy poly (ethylene glycol) ether (APEG)-based PCE (APEG PCE) synthesized by maleic anhydride has strong calcium ion binding ability and superior dispersity. The acid ether ratio of polyethylene glycol methallyl ether (HPEG)-based PCE (HPEG PCE) is 7, the side chain length is 7 epoxy ethane (EO), and the structural sequence with more AAA (A= acid monomer) and AAE (A= acid monomer, E= HPEG) is beneficial for improving the flowability and workability of AAS slurry. There is no correlation between the solubility and dispersity of PCE in AAS slurry. And the current research problems and future research directions of PCE in AAS cementitious materials to promote the green and low-carbon development of the construction industry are proposed.