Sodium-ion batteries with potentially low cost is an alternative to lithium-ion batteries for large-scale energy storage. However, developing high energy density and ultralong cycle life electrodes for sodium-ion batteries is a key issue due to the larger radius of Na+ than Li+ and the sluggish sodium intercalation kinetics. One-step electrospinning process has been applied to synthesis Sb2S3 nanocrystals hosted in multichannel porous N-doped carbon nanofiber (CNF). Sb2S3 nanoparticles with diameter of 10–50 nm were uniformly embedded in CNF, while the multichannel pores of CNF act as a buffer to restrict the volume expansion of Sb2S3 during cycling. Sb2S3@N-doped carbon nanofiber (Sb2S3@CNF) delivered a specific capacity of 311 mAh g−1 at 100 mA g−1 with a capacity retention of 87% after 1000 cycles at 1A g−1, corresponding to a capacity decay rate of only 0.013% per cycle. Benefited from the unique multichannel mesoporous structure, charge storage of Sb2S3@CNF is mainly contributed by a surface capacitive process indicating significantly enhanced mass diffusion properties. The as-developed nanofibers with a cylindrical porous structure by a one-step electrospinning method can be an excellent host for electroactive materials to achieve ultralong cycle life.