Metal-air batteries and supercapacitors have gained growing attention in wearable devices due to their high energy density, long shelf life, low cost and environmental compatibility. The suitable electrocatalysts for these metal-air batteries still remain a critical issue in order to achieve high energy density, large capacitance, and long stability. Recently, manganese oxides show some potentials, but require to be mixed with conductive additives to leap over the limitations of small current densities and large overpotential. In this work, we utilize a novel trifunctional catalyst consisting of intertwined MnO₂/carbon nanotubes (MnO₂/CNTs) hybrid with flexible morphology by a two-step hydrothermal method. The hybrid catalyst exhibits a high electrochemical activity (ΔE: 0.98 V), power density and charge-discharge (C-D) stability relative to the Pt/C catalyst. More importantly, the flexible MnO₂/CNTs catalyst improves the flexibility and stability of wearable energy devices.