To meet the ultra-precision and the high-speed displacement measurement requirements of high-end equipments, such as microelectronic lithography machine, the research group from Harbin Institute of Technology has thoroughly explored the traditional heterodyne laser interferometry with coaxial beams and new heterodyne laser interferometry with non-coaxial beams. The group has achieved continuous breakthroughs in many key technologies, including the high-precision laser frequency stabilization, precise suppression of optical nonlinear errors, and high-speed and high-resolution interference signal processing. The group has also developed a series of ultra-precision and high-speed laser interferometers with a vacuum-wavelength relative accuracy up to 9.6 × 10^-10, displacement resolution of 0.077 nm, minimum optical nonlinear error of 13 pm, and maximum measuring speed of 5.37 m/s. Currently, these interferometers have been successfully used in integration development and performance test of lithography machine prototypes with nodes ranging from 350 nm to 28 nm and have provided important technical support and measurement methods for high-end equipments in China.