The invention relates to a preparation method of an energy absorbing device of a composite origami structure. Firstly, an origami rubber mold cavity and a support gasbag are assembled, the support gasbag is filled with light gas, then the surface treatment is performed on the origami rubber mold cavity, then fiber cloth is laid on the surface of the rubber mold cavity, the fiber cloth is fully soaked in resin by adopting a vacuum infusion process and is solidified and formed, and finally, a demolding process is adopted, so that the energy absorbing device of the composite origami structure canbe obtained. Compared with the prior art, the preparation method has the advantages that the problems of high manufacturing cost, heavy dead weight and limitation to the shape and dimension of the origami structure when the origami energy absorbing structure is manufactured by adopting metal materials are greatly solved, the preparation method is suitable for manufacturing origami energy absorbing structures of various shapes and dimensions, the manufacturing is easy, the manufacturing cost is low, the effects of simplicity and practicability are achieved, and the operation and popularizationare easy.