The invention relates to a preparation method of a flexible and foldable all-organic secondary battery, and belongs to the technical field of electrochemical power sources. The preparation method of the flexible and foldable all-organic secondary battery comprises the following steps: (1) preparation of an anode material and a thin film, namely adding naphthalenetetracarboxylic dianhydride and 4,4'-diaminodiphenyl ether to an n-methyl pyrrolidone (NMP) solution, adding a graphene conducting agent and carrying out reflux reaction in an argon atmosphere to prepare the film; (2) preparation of a cathode material and the thin film, namely putting ferrocene, tetramethylethylenediamine and n-butyl lithium into a Schlenk reaction bottle, adding petroleum ether, reacting and precipitating the mixture, cleaning the sediment with a solvent, adding the petroleum ether, dropwise adding hydrogen methyl dichlorosilane, and carrying out thermochemical polymerization on solid to prepare the film; (3) preparation of polymer gel electrolyte, namely mixing polyvinyl pyrrolidone with NaCl/H2O liquid; and (4) battery assembly, assembling the cathode material film, the anode material film and the gel electrolyte into the battery. The preparation method has the advantages that the process is stable; the product is ultrathin, controllable, flexible, foldable, easy to design, safe and nontoxic, and can meet the requirements of human body fitting comfort and special occasions.