The invention discloses a polyvinylidene fluoride film with a bionic triply periodic minimal surface structure and a preparation thereof, and application of a polyvinylidene fluoride film with a bionic triply periodic minimal surface structure. The polyvinylidene fluoride film takes a sea urchin shell with the triply periodic minimal surface structure as a template and is obtained by the followingmethod, wherein the method comprises the steps of: preparing the sea urchin shell into sea urchin shell slices with the thickness of not more than 160 [mu]m, permeating PVDF into the skeleton of thesea urchin shell slices by virtue of a solvent and completely filling the skeleton, and soaking the sea urchin shell slices filled with the PVDF by using acid to remove a sea urchin shell template toobtain the polyvinylidene fluoride film with the bionic triply periodic minimal surface structure. When the polyvinylidene fluoride film with the bionic triply periodic minimal surface structure is used as a lithium metal battery diaphragm, the cycling stability of the lithium metal battery can be obviously improved.