The invention relates to a composite transparent conductive film and a preparation method thereof. The preparation method comprises the following steps of S1, performing catalytic growth of a single-crystal-layer graphene film on the surface of a metal substrate, and obtaining a structure I; S2, plating a silver nanometer wire on the surface of the graphene film of the structure I, thereby obtaining a composite structure II; S3, uniformly plating a liquid photo-curable material on a flexible transparent substrate, thereby obtaining a composite structure III; S4, performing aligned pressing on the liquid photo-curable coating in the composite structure III and the silver nano-wire coating in the composite structure II, thereby obtaining a composite structure IV; S5, performing irradiation on the composite structure IV so that the liquid photo-curable coating is converted to solid, thereby obtaining a composite structure V; and S6, through an electrochemical stripping method, separating a metal substrate in the composite structure V, thereby obtaining a composite conductive flexible film. The preparation method has advantages of simple operation, high reliability and high suitability for large-scale production. The prepared composite transparent conductive film has advantages of excellent conductivity, high transmittance and reliable performance.