Spinal cord injury (SCI) is a severe traumatic lesion of the central nervous system, in which patients present with sensory, motor and autonomic nerve dysfunction below the level of the injury. Neural stem cells (NSCs) possess robust self-renewal capacity, multi-directional differentiation potential, and unique microenvironment regulatory functions. This article focuses on elaborating the mechanisms of NSCs transplantation for the treatment of SCI. Studies have shown that NSCs can not only differentiate into nerval cells, but also play a crucial role in neuroprotection, axonal regeneration, and neural circuit reconstruction through complex intercellular interactions and microenvironment regulatory mechanisms. However, NSCs transplantation for the treatment of SCI still faces challenges such as low survival rate of transplanted cells, insufficient efficiency of directed differentiation, and obstruction by glial scarring. Future studies may integrate genetic technologies and utilize biomaterials to enhance cell survival capacity and improve the damaged microenvironment, thereby advancing the researches on NSCs transplantation for SCI from basic studies to clinical application and bringing new hope to patients with SCI.