Pliable composite films were prepared based on phase change materials (PCM) through the following steps. Firstly,octadecane/nature rubber latex with high stability was prepared with composite emulsion technology. Secondly,phase change pliable composite films with complex shape were prepared through dipping process. Finally,major properties of the composite films were measured,including mechanical property,thermal property and sealing property. Results show that the composite PCM film is a favorable energy storing media with latent heat of 237.1 kJ·kg^{-1. It also has excellant mechanical and air-proof properties with elongation factor at divulsion of 1135% and air transmission coefficient of 3.71×10-17 m2·Pa－1·s－1 respectively. Therefore,it can be used for energy storing purpose of geometrically complicated structure.}