Freestanding N-doped carbon coated Fe3O4 particles nanocomposites with three dimensional (3D) carbon fibers network (NC@Fe3O4/CF) derived from bacterial cellulose (BC) was fabricated by simple hydrothermal and carbonization. This self-supporting structure, as promising electrode without current collector or conductive additive, showed high area capacitance and volume capacitance (1.36F·cm−2, 2300F·cm−3 at 3mA·cm−2). Simultaneous, the electrode showed good cycle life (88.5% capacitance retention over 4000cycles) and wide potential window (−1.2 to 0V), possessed the property of pseudo and carbon materials. This low-cost, non-toxic and high capacity freestanding electrode is a potential candidate for supercapacitor applications.