The invention discloses a preparation method for a carbon nanotube-load graphene-copper nanoparticle composite flexible conductive film, and belongs to the technical field of preparation of a conductive thin film and preparation of a composite material. The method comprises the steps of atomizing a copper salt solution and a graphene oxide suspension liquid by a spray pyrolysis method on the basisof a carbon nanotube conductive thin film which is prepared in advance, forming nucleation on a conductive nanotube conductive thin film carrier after pyrolysis, growing to generate graphene-copper oxide, and finally performing reduction to obtain a copper-graphene-carbon nanotube flexible conductive thin film belt. The detection result shows that the grain size of copper is 200 nanometers or below, the graphene-copper is uniformly arranged and embedded onto the carrier, and the conductivity of the copper-graphene-carbon nanotube flexible conductive thin film belt is improved by one order ofmagnitude; and moreover, the preparation method of the carbon nanotube-loaded graphene-copper for the flexible conductive film is simple and easy to operate, large-size equipment is not needed, and the process flow is relatively short.