本文提出了一种新的测量多层光学薄膜参数的方法。利用玻璃载物片夹一层水再夹一层酒精构成了含有两层准光波导薄膜的多层薄膜结构。观察并测量了这两层准光波导的m线,得到了薄膜的光学参数。薄膜折射率的测量误差为±1×10~(-3),薄膜厚度的测量误差为±0.1μm。 This paper presents a new method for measuring the parameters of multilayer optical thin films. Using a glass slide containing a layer of water and then sandwiching a layer of alcohol, a multilayer thin film structure comprising two layers of quasi-optical waveguide films is formed. The m-line of these two layers of quasi-optical waveguides was observed and measured, and the optical parameters of the films were obtained. The measurement error of film refractive index is ± 1 × 10 -3, and the measurement error of film thickness is ± 0.1 μm.