通过正硅酸乙酯（ＴＥＯＳ）在聚酰胺酸（ＰＡＡ）的Ｎ，Ｎ’二甲基乙酰胺（ＤＭＡｃ），溶液中进行溶胶凝胶反应，制备出不同二氧化硅含量的聚酰亚胺／二氧化硅（ＰＩ／ＳｉＯ２）复合薄膜材料．二氧化硅含量低于１０ｗｔ％的样品是透明浅黄色薄膜；二氧化硅含量高于１０ｗｔ％的样品是不透明棕黄色薄膜．利用红外光谱、扫描电镜、热失重分析、动态力学分析、热膨胀系数测试和应力应变测试等方法研究了此类材料的结构与性能．结果表明，ＰＩ／ＳｉＯ２纳米复合材料具有较聚酰亚胺更高的热稳定性和更高的模量；线膨胀系数显著降低；拉伸强度和断裂伸长随二氧化硅含量而变化，分别在１０ｗｔ％和３０ｗｔ％附近出现最大值 The polyesters with different silica contents were prepared by sol-gel reaction of tetraethyl orthosilicate (TEOS) in N, N’-dimethylacetamide (DMAc) solution of polyamic acid (PAA) Imine / silicon dioxide (PI / SiO2) composite film material. Samples with silica content below 10 wt% were clear, light yellow films; samples with silica content above 10 wt% were opaque tan films. The structure and properties of these materials were investigated by IR, SEM, TG, dynamic mechanical analysis, CTE and stress-strain tests. The results show that the PI / SiO2 nanocomposites have higher thermal stability and higher modulus than polyimide, the linear expansion coefficient is significantly reduced, and the tensile strength and elongation at break change with the silica content, respectively The maximum appears around 10 wt% and 30 wt%