The work aims to study the chemical and mechanical polishing (CMP) mechanism of cemented carbide tool ma-terial, so as to provide theoretical support for improving the surface quality of cemented carbide tool. The chemical reaction of cemented carbide tool material in acid polishing solution was analyzed and the chemical reaction mechanism of cemented carbide tool material CMP was studied. The actual contact area between polishing pad and workpiece and the actual cutting area of a single abrasive particle were calculated based on contact mechanics theory, the material removal rate model of cemented carbide tool material CMP was established on the basis of kinematics analysis, and the effectiveness of the material removal rate model was verified by experiments. In acid polishing solution, cemented carbide tool was oxidized to Co3O4. When the workpiece, polishing pad, abrasive particle type and installation position were determined, the material removal rate was related to polishing load, abrasive particle concentration and polishing disc speed. The correction coefficient Kcmwas 8.53 for the YG8 tools CMP under common cemented carbide polishing conditions, and the lowest surface roughness of the polished tools could reach 48 nm. At this time, the material removal rate was 62.381 nm/min and the maximum relative error between the theoretical value and the experimental value of material removal rate was 13.25%. Thus, surface defects were eliminated and good mirror effect was obtained. The material removal rate model is effective certainly, and CMP of cemented carbide tool material can eliminate the surface defects of the tool and improve surface quality.