With the current rapid growth of commercial applications for flexible and wearable optoelectronic devices, flexible power sources are very much in demand. Herein, a facile strategy to grow cobalt nanoparticles encapsulated in nitrogen-doped carbon nanotube arrays on flexible carbon fiber cloth as self-supported electrodes for high-performance flexible zinc–air batteries is developed. Benefiting from high electrical conductivity and multiple active sites as well as free polymer binder, the self-supported electrode exhibits excellent electrocatalytic activity. The maximum power density of a zinc-air battery using the self-supported electrode as air cathode is higher than that of the zinc-air battery with Pt/C+IrO2 as air electrode. Furthermore, the zinc-air battery can be stably operated under external stress without obvious loss of the electrochemical performance. This work opens up a new pathway for the rational design of flexible electrodes for high-performance flexible power sources.