The work aims to prepare cellulose nanofibers with bamboo powder as the raw material and prepare cellulose nanofibers (CNFs)/multi-walled carbon nanotubes (MWCNTs)/silver nanowires (AgNWs) composite electrode with cellulose nanofibers as the substrate. The composite electrode can be applied for the flexible supercapacitor. First, we used bamboo powder coming from nature for raw material and the aqueous CNFs suspension were prepared by chemical treatment, one time-pass grinding and sonication successively. The multi-walled carbon nanotube and silver nanowire were ultrasonically dispersed in the solvent, respectively. Finally, the CNFs/MWCNTs/AgNWs composite electrode was prepared by layer by layer method. As the control group, cellulose nanofibers/multi-walled carbon nanotubes composite electrode was prepared. Cellulose nanofibers, the diameter of which was about 30~100 nm, intertwining into a net structure, were good supporting materials. CNFs/MWCNTs/AgNWs composite electrode could be bent and the specific capacitance of it reached 77.95 mF/cm2 at 30 mV/s. With cellulose nanofibers as the substrate, the CNFs/MWCNTs/ AgNWs composite electrode prepared through layer by layer method has better electrochemical performance and it can be used as the electrode for flexible supercapacitor.