Cadmium zinc telluride (CZT) wafers are the ideal semiconductor materials for manufacturing high-energy ray detectors at room temperature,and obtaining high-quality CZT wafers is of great significance for improving detection performance.Based on the chemical mechanical polishing (CMP) process,the four-factor three-level orthogonal CMP experiments including abrasives size and mass fraction,pH values of polishing slurry,polishing pressure were designed and carried out. After CMP processing,an ultra-smooth surface with a minimum average roughness of 0.289 nm in the range of 200 μm×200 μm is obtained.Through the mean and range analysis of the test results,it is concluded that the pH values and the abrasives mass fraction have a greater impact on the CMP performance,and the stronger acid and larger mass fraction of abrasives are beneficial to improve the chemical dissolution and mechanical grinding of CZT wafers,respectively.The CMP optimization scheme for CZT wafers was proposed.Through X-ray photoelectronic energy spectrum (XPS) characteristics, the chemical corrosion of acidity,which has the greatest effect on polishing performance was explored,and the material removal mechanism of “oxidation-etching-chelation-grinding” in the CMP process of CZT wafers was revealed.