Poor electrical conductivity and large volume changes are two disadvantages of metal selenides. In this work, MnSe nanoparticles encapsulated into N-carbon fibers are designed and prepared using electrospinning and calcination methods. When calcined at 700 °C, the composite has a high reversible capacity of 684 mAh g−1 after 100 cycles at 0.1 A g−1, owing to the improved conductivity and protection provided by carbon fibers. Furthermore, the in situ electrochemical impedance measurements reveal the process kinetics of the composites. This work will provide the basis for the further development of the application of metal selenides in the field of flexible electrodes.