Hierarchical pore structures in the composite electrode materials can offer greater accessibility to active sites for the lithium ions, shorter ion diffusion distances and quicker lithium ion diffusion, which can enable the high-rate and high-energy Li-ion batteries (LIBs). In this work, hierarchically porous cocoon-like MnO/C composites (PCM) have been prepared using natural agaric as raw materials via a sustainable and facile method associated with the hydrothermal and annealing treatment. The as-prepared porous PCM composites show a high reversible capacity of 981 mAh g−1 at 0.1 A g−1 and remain an high discharge capacity of 640 mAh g−1 after 900 cycles at 1 A g−1. Even at the high current density of 5 A g−1, the electrode can still deliver a high capacity of 440 mAh g−1. More importantly, the high MnO content (∼78 wt %) and micron-scale structure of PCM composite greatly improve the high specific capacity and tap density of electrode materials, and help to meet the requirements for practical application. Therefore, such novel preparation strategy of composite electrode from agaric also develops a new route to fully utilize the biomass resources for high-performance LIBs and other energy storage devices.