为揭示超薄膜的特性与其微观结构的关系 ,运用分子动力学模拟的方法进行了研究。模拟系统采用云母晶面作为固体壁面 ,十六烷采用珠簧模型。模拟表明 ,超薄膜状态下流体出现了层状的类固态微观结构。采用固液比作为类固态与类液态的比例指标 ,发现等效粘度的上升是薄膜流体类固化造成的。模拟发现了摩擦力的非线性特性 ,这种非线性与超薄膜微观结构的变化具有较好的对应性 In order to reveal the relationship between the properties of ultrathin films and their microstructures, the molecular dynamics simulation method was used to study the relationship between the properties and the microstructure. The simulation system uses mica crystal face as the solid wall, hexadecane adopts the bead spring model. The simulation shows that the layered solid-like microstructure appears in the ultra-thin film. The ratio of solid to liquid was used as the index of the ratio of solid to liquid. It was found that the increase of equivalent viscosity was caused by solidification of thin film fluid. The simulation found the nonlinearity of the friction force. This nonlinearity has a good correspondence with the change of the microstructure of the ultrathin film