The invention provides a composite structural member capable of storing/releasing charge and a preparing method and application thereof. The composite structural member is stacked by structural member monomers of a laminated structure, and two sides of the structural member monomers are symmetrical outwards from the center, and successively comprise an electrolyte membrance, an aelectrolyte, a conductive electrode, a current collector, and an insulation and encapsulating layer from center to outside; by utilizing composite forming processes, composite structural members capable of circulating storage/ releasing charge can be prepared, which are of different shapes and structures, such as a circular pipe, a C-shaped beam, an I-shaped beam, etc. The composite structural member has the functions of mechanics and energy storage, can effectively reduce the weight and size of a storage unit in a traditional electric system, and realize system comprehensive optimization, is safe and reliable, and has a bright application prospect in the fields such as new electrical vehicle, national defense, aerospace, new energy resources, etc.