The invention provides a kind of carbon nanotube / short-fiber composited nano-carbon paper and a continuous preparation method thereof. The nano-carbon paper mainly comprises disordered carbon nanotubes and short fibers, and is in a non-woven form. The preparation method of the nano-carbon paper comprises the following steps that: the disordered carbon nanotubes are dispersed in a solvent so as to form a dispersion liquid; then, mixing and dispersing the short fibers so as to form a size; preparing an initial film through vacuum assisted flow-casting film-forming; and then, removing polymers in the initial film through subsequent processing so as to obtain a target product. The composited nano-carbon paper disclosed by the invention integrates the huge specific surface areas, superior conductivity and functional characteristics of the carbon nanotubes and the enhancement effect of the short fibers on the strength and flexibility of the carbon paper, therefore, the composited nano-carbon paper is good in self-supporting property and flexibility; meanwhile, through the direct film-forming implemented by using a flow-casting method, the continuous film-forming of the nano-carbon paper is realized, therefore, the nano-carbon paper has the advantages of high efficiency, rapidness and easy large-scale preparation. The composited nano-carbon paper disclosed by the invention has a wide application prospect in the fields of energy electrodes, catalytic carriers, environmental management, static resistance, electromagnetic shielding, wave-absorbing camouflage, and the like.