Bismuth-based materials are promising alloy-type materials as lithium-ion batteries (LIBs) anode with a high theoretical capacity of about 385 mAh g−1 (Li3Bi). However, the severe volume change during the charge/discharge process limits their applications in LIBs. Nanostructured design is an effective strategy to relieve the volume change. Here, Bi5Ni3O15 nanowires are designed and fabricated via a sample electrospinning technique. When used as anode material, the Bi5Ni3O15 nanowires exhibit a charge/discharge capacity of 372 and 636 mAh g−1 at current density of 100 mA g−1. After 100 cycles, it still retains a capacity of 267 mAh g−1, revealing a good electrochemical performance. This is mainly attributed to the nanostructured design, which can suppress the pulverization resulting from volume variation during the repeated alloy/dealloy process and offers shorter lithium-ion diffusion path together. In addition, in-situ X-ray diffraction experiments are carried out to explore the phase change and lithium storage mechanism. The exploration of Bi5Ni3O15 nanowires as LIBs anode demonstrates that nanostructured design is an effective approach to improve electrochemical performance of alloy-type anodes, which will speed up the process to develop novel alloy-type anodes.