Laser interferometer has the advantages of high measurement resolution and traceability of measurement results, and is increasingly widely used in nanometer measurement. The Michelson laser interferometers used in nano-measuring machine and linear expansion coefficient measuring device for low expansion materials, and the Fabry-Perot laser interferometer used in high-precision displacement measuring device are introduced in this paper. Combined with these typical applications , key problems in the interferometer optical system design, measurement environment control, the nonlinear error compensation of Michelson interferometer and the measurement range expansion of Fabry-Perot interferometer are analyzed and summarized. The principles and methods described in this paper are of great significance for the laser interferometer to achieve nanometer measurement accuracy, which can provide technical reference for the development of high-precision laser interferometer and wider applications of laser interferometers in nanometer measurements.