Graphene/cotton fibers show significant promise in wearable energy storage due to their low cost, porous structure, and exceptional integration ability into wearable systems. However, the eco-unfriendly reductants and standalone electric double-layer capacitor hindered their application. Herein, a green and rapid hydrothermal-electrodeposition method was proposed to fabricate polyaniline (PANI) decorated reduced graphene oxide (rGO)/cotton yarns without using any chemical reductants and oxidants. The PANI/rGO/cotton (PRC) yarn exhibited porous conductive network, structural controllability, and mechanical flexibility. Additionally, the PRC yarn electrode delivers a fast electron transport and ion migration, synergistic energy storage contribution, and a controllable capacitance (up to 81.2 mF cm(-1) at 0.2 mA cm(-1)). The assembled yarn supercapacitor shows a good capacitance (19.8 mF cm(-1) at 0.08 mA cm(-1)), excellent energy-power density (2.7 mu Wh cm(-1) at 40 mu W cm(-1)), and great capacitance retention. This green fabrication of PRC yarns brings new insights into the development of wearable energy storage.