Abstract: Using nanocellulose(CNF), carboxylated carbon nanotubes(CNTs—COOH), pencil graphite(PGr) and polypyrrole(PPy) as raw materials, the CNF-CNTs—COOH-PGr/PPy flexible electrode composite with graphite layer structure was prepared by vacuum filtration, coating, oxidative polymerization and based on the principle of hydrogen bonding interface interaction. The results show that the CNF-CNTs—COOH-PGr/PPy flexible electrode composite does not break when it is flatted, folded and stretched, and exhibits strong mechanical properties, and its tensile strength reaches 28.90 MPa. The porous structure of hydrophilic CNF and CNTs—COOH enhances the diffusion path of ions and electrons. The addition of PGr effectively improves the conductive path of CNF-CNTs—COOH-PGr/PPy flexible electrode composite and gives it excellent conductive properties. The conductivity of CNF-CNTs—COOH-PGr/PPy flexible electrode composite obtained after the oxidative polymerization reaches 5.403 S·cm⁻¹. In the 1 mol·L⁻¹ H₂SO₄ solution, the CNF-CNTs—COOH-PGr/PPy flexible electrode composite has a high specific capacitance of 521 F·g⁻¹ at the current density of 0.5 A·g⁻¹. And its capacitance retention rate is as high as 68% after 1 500 charge and discharge cycles. Based on the excellent mechanical properties, the electrochemical properties and electrical conductivity of the flexible electrodes, the CNF-CNTs—COOH-PGr/PPy flexible electrode composite has the basis characteristics for becoming the electrode material for flexible energy storage devices.