Abstract: Chemical mechanical polishing(CMP)method and self-made alumina polishing liquid were used to polish zinc selenide wafer.The polishing experiments were carried out for the influence of particle size of alumina polishing liquid,pH value,type and content of oxidizing agent on the surface state and removal rate of zinc selenide wafer.The results showed that alumina polishing liquid was suitable for the polishing and that the quality was better when the parameters were aluminum oxide particle size 200 nm(mass fraction of alumina 15%),soaked for 24 h with NaClO(mass fraction 3%)and pH value 8.The final removal rate was 2 μm/min and surface was smooth without scratches.