Indium antimonide (InSb) is a widely used material in mid-wave infrared detection. The surface roughness of polishing wafer is the key index that affects the performance of devices. The influence of pH value of InSb chemical mechanical polishing solution, the proportion of oxidant and the flow rate of the polishing solution on the surface roughness of InSb polishing wafer were studied. The surface roughness of the polishing wafer was characterized and optimized by atomic force microscope (AFM) and the surface profilometer. The results show that the surface roughness of InSb wafer is 1.05 nm (AFM) when the pH is 8, the proportion of oxidant is 0.75%, and the flow rate of polishing solution is 200 L/min. At the same time, the polishing macro quality of the wafer is better.