Graphene is a typical two-dimensional monatomic-layered material and has high theoretical electrochemical capacitance. The working mechanism of graphene supercapacitors is investigated. The deformation properties of flexible supercapacitors based on graphene electrodes are studied. The type of deformations can be extended from static bending, curl and stretching to arbitrary even dynamic deformation. Finally, the application prospect of flexible graphene supercapacitors is envisioned in portable electronics.