The laser interferometer uses light waves as the carrier, and has the characteristics of high measurement accuracy, fast measurement speed, large measurement range and high resolution at the highest speed. The wavelength of the light wave can directly define the meter and trace it to the national standard. Therefore, laser interferometers are widely used in the quality control and calibration of precision instruments such as CNC machine tools, PCB drilling machines, coordinate measuring machines, displacement sensors, as well as research and development, high-end equipment manufacturing and other fields.