The invention discloses a preparation method of a cellulose nano-whisker/graphene flexible transparent conductive film. Tea-oil tree shell is taken as the raw material, and tea-oil tree shell cellulose nano-whiskers are obtained by separation through the main steps of cooking through an alkali method, alkali treatment, purification, bleaching, acidolysis, centrifuging, dispersing and the like; theobtained cellulose nano-whiskers are large in specific surface area, high in Young modulus and high in reactivity; next, suction filtration is performed to obtain a substrate film which is uniform and smooth in surface, and relatively high in flexibility, light transmission, mechanical property and thermodynamic property; by taking graphene as a conductive matrix, and under the effect of CTAB, the graphene is uniformly paved on the surface of the substrate film through a suction filtration method to form a uniform and a continuous conductive layer; and by controlling the adding amount of graphene and the number of layers of graphene on the surface of the film, the prepared flexible transparent conductive film has relatively high flexibility, foldable property, elasticity, rigidity and thermal stability and bright application prospect.