从薄膜的导纳入手，分析了多层薄膜的相位特点和波长与相位的变化关系。计算了高反薄膜的相位变化，分析了光学薄膜的相位对光学器件的影响。 Starting from the admittance of the film, the phase characteristics and the relationship between the wavelength and the phase of the multilayer film were analyzed. The phase change of the high anti-thin film was calculated and the influence of the optical film phase on the optical device was analyzed.