The invention discloses a flexible 
film capacitor with 
high energy storage density. The flexible 
film capacitor comprises a flexible 
polymer substrate and at least one 
film capacitor energy storage film layer vertically stacked on the substrate, wherein each film 
capacitor energy storage film layer comprises a lower transparent 
electrode layer, a lower modification layer, a high-
dielectric-constant 
energy storage film layer, an upper modification layer and an upper transparent 
electrode layer which are vertically stacked on the flexible 
polymer substrate in sequence from bottom to top; the upper transparent 
electrode layer and the lower transparent electrode layer are interdigital electrodes; the transparent electrode layer is made of 
graphene, ITO or AZO; the energy storage film layer ismade of Al2O3, HfO2, TiO2, ZrO2 or BZN; and the upper modification layer and the lower modification layer are made of 
graphene-like materials such as WS2, MoS2 and WSe2 or ZnO and GaN. The 
capacitor is simple in structure and preparation process and easy to produce in batches; 
raw material cost is low; the 
tungsten disulfide film is compact and large in specific surface area, the contact interfacequality of the electrode layer and the 
dielectric layer is greatly improved, and the 
storage energy is increased.