A superplasticizer (WPS) was synthesized from waste plexiglas and sodium allysulfonate in this paper. Poly (methyl methacrylate-co-ethyl acrylate) grafling sodium allysulfonate (PMMA-g-AS) was prepared through reactive extrusion in self-single screw extruder and hydrolysis reaction. The structures of the WPS was characterized by FT-IR spectrometer. The results show that structure of the WPS are clear. By using UV-visible adsorption spectrophotometer, micro-electrophoresis potential analyzer, and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. The results indicated that the adsorption behavior of WPS on gypsum particles follows a Langmuir isothermal adsorption model with an adsorption heat of 18.79 kJ/mol and an adsorption layer thickness of 17. 52 nm. Adsorption isotherm suggested that Langmiur single layer adsorption occurred during the process of adsorption of WPS and FDN on gypsum particles.