采用复合靶共溅射方法制备了（Ａｕ，Ａｇ）／Ｓｉ复合纳米颗粒薄膜，分别采用ＭａｘｗｅｌＧａｒｎｅｔ理论和微分有效媒质（ＤＥＭ）理论计算了Ａｇ／Ｓｉ复合薄膜的吸收光谱，实验测量结果与ＤＥＭ理论计算更接近，讨论了（Ａｕ，Ａｇ）／Ｓｉ体系复合薄膜共振吸收峰宽化的微观机制． The (Au, Ag) / Si composite nanoparticle films were prepared by co-sputtering of composite targets. The absorption spectra of Ag / Si composite thin films were calculated by MaxwelGarnet theory and differential effective medium (DEM) The results are close to the DEM theoretical calculations. The microscopic mechanism of resonant absorption broadening of (Au, Ag) / Si composite thin films is discussed.