The global concrete industry is actively committed to promoting energy conservation and carbon emission reduction. This trend accelerates the widespread application of low-carbon binders. As a technology of low-carbon binders continues to advance, the development of polycarboxylate-based superplasticizer (PCE) suitable for low-clinker or clinker-free binding systems becomes increasingly important. This review represents the classification, the principle of structural design, synthetic methods, and performance characteristics of PCE. The latest development and technological innovation of PCE are described, in particular emphasizing on some challenges faced by PCE in specific application scenarios of low carbon blended cementitious system. The review also looks ahead to the technological prospects of PCE and its key development directions in achieving the low-carbon transformation of the concrete industry.PCE is a polymer designed via introducing different monomer types into its molecular main chain. These monomers include methoxy polyethylene glycol methacrylate (MPEG), allyl polyoxyethylene ether (APEG), methallyl polyoxyethylene ether (HPEG), isopentenyl polyethylene glycol ether (IPEG), and 4-hydroxybutyl vinyl polyoxyethylene ether (VPEG), each imparting distinct physical and chemical properties to PCE. For instance, MPEG-based PCE exhibits a remarkable water reduction rate and has a higher viscosity, thus restricting its application due to time-consuming synthesis. In contrast, VPEG-based PCE requires shorter synthetic time and lower reaction temperature, which demonstrates superior flowability and slump retention, making it suitable for application scenarios requiring prolonged water retention. Besides the choice of monomer types, the structural design of PCE involves other factors, i.e., molecular weight, charge density, and side chain length, etc.. These factors collectively determine the performance of PCE in cement-based materials, including workability, strength development, and long-term durability. The modifications to the main chain of PCE such as silane or phosphate groups can enhance sulfate resistance and adsorption capacity. Lignin-based framework modification of PCE employs readily available raw materials but performs better than traditional PCEs. Anionic side chain modifications and those with large terminal groups can significantly alter PCE’s slump retention and clay tolerance. The development of C-S-H-PCE greatly improves the early strength performance of concrete.Regarding the synthesis methods, PCE is typically prepared through free radical polymerization, which can be conducted in aqueous solution or via emulsion or microemulsion. The determination of synthesis conditions, i.e.. temperature, pressure, catalyst type, and agent concentration are crucial for achieving high-performance PCE. Also, adjusting the monomer ratio of polymer formulation can further enhance PCE performance to meet specific engineering requirements. Other PCE synthesis techniques encompass reversible addition-fragmentation chain transfer polymerization (RAFT) and atom transfer radical polymerization (ATRP). Compared to the simplest approach of free radical polymerization that cannot precisely control molecular weight and structural sequences, the RAFT process allows for customized PCE molecular structures through RAFT agents. The structure-activity relationship between molecular architecture and dispersion performance can be established via continuously innovating PCE synthesis methods e.g., RAFT and ATRP, thus facilitating the development of highly efficient and eco-friendly PCE polymers.In response to the increasing demands for the sustainability of construction industry, the carbon footprint of PCE additives is accurately assessed, whereby the sources of carbon emissions during PCE production and application are identified. Consequently, green high-performance PCEs begin to be developed, delivering remarkable water-reducing efficiency and obtaining other properties such as improvement of early strength and reduction in dry-shrinkage cracks. Particularly for the development of low carbon cementitious systems, the application of PCE is crucial but currently encounters serious compatibility issues. For instance, some issues related to dispersion failure of PCE in alkali-activated cementitious materials remain unclear. Ensuring desirable workability and adaptability of PCE in low carbon binders is a challenge posed in these systems.Summary and ProspectsTo address these challenges, some solutions are explored. On one hand, the molecular structure of PCE is improved to enhance its stability and adaptability in complex environments. On the other hand, some concepts from nanotechnology and smart materials are proposed to develop self-healing PCE products. These innovative studies can improve the overall performance of concrete and pave some effective pathways for the green development of the construction industry. Polycarboxylate superplasticizers play a vital role in driving the concrete industry towards energy saving and emission reduction. A future research will focus on enhancing PCE performance, cost reduction, and expanding its application fields. With the advancement of technology and the guidance of innovative thinking, we can believe that PCE will play an even greater role in promoting sustainable development in the construction industry.