The absorption characteristics of cationic polyelectrolyte PDADMAC and anionic polyelectrolyte PSS on benzoguanamine formaldehyde (BGF) particles are investigated. The charging characteristics of BGF particles are changed and controlled using electrostatic self assembly method. A variety of PEi BGF/SiO2 composite abrasives are obtained. The as prepared samples are analyzed by Zeta potential analysis, transmission electron microscope (TEM) and thermogravimetric (TG) analysis. The composite abrasives slurries are prepared for copper polishing. The polishing results indicate that it is SiO2 abrasives, not only coated SiO2 abrasive on polymer particles but also free SiO2 abrasive in slurry, that offer the polishing action. The material removal rates of copper polishing are 264 nm/min, 348 nm/min and 476 nm/min using single SiO2 abrasive slurry, PE0 BGF/SiO2 mixed abrasives slurry and PE3 BGF/SiO2 composite abrasives slurry respectively. The surface roughness Ra of copper wafer (with 5 μm×5 μm district) is decreased from 0.166 μm to 3.7 nm, 2.6 nm and 1.5 nm, and the surface peak valley values Rpv are less than 20 nm, 14 nm and 10 nm using these kinds of slurries respectively.