利用基于激光外差测量技术和激光多普勒技术的非接触式多光束激光外差测量方法,得到了光电探测器输出电流的谐波表达式.讨论了该测量方法用于玻璃厚度超精密测量的可行性及理论依据,并利用Matlab软件对不同情况进行了仿真实验.结果表明:该方法在不同入射角时测量平板玻璃厚度最大的误差为0.3%,明显比其他测量方法精度高. The harmonic expression of photodetector output current is obtained by the non-contact multi-beam laser heterodyne measurement method based on laser heterodyne measurement and laser Doppler technique. The measurement method is discussed for ultra-precision measurement of glass thickness The feasibility and theoretical basis of this method are also discussed.And the simulation experiment is carried out by using Matlab software.The results show that the error of the maximum thickness of flat glass measured at different incident angles is 0.3%, which is obviously higher than other measurement methods.