Objective To investigate the effect of necrostatin-1 on locomotor recovery after spinal cord injury (SCI) in mice, and to explore the role of apoptosis and M1 type-microglia/macrophage-mediated pro-inflammation in the protective effect. Methods Male C57BL/6 mice were randomly divided into four groups: control group, necrostatin-1 group, SCI model group, necrostatin-1-treated group after SCI, with 20 mice in each. For SCI model group, mice were anesthetized with 10 g/L pentobarbital sodium with a dose of 8 mL/kg. After skin disinfection, T8 laminectomy was performed under operating microscope, and the T8 spinal cord was clearly revealed. The injury model was established with a device designed by our own with the parameter at 0.2 mm-width for 20 seconds. Manual urination was performed once a day. For necrostatin-1-treated group after SCI, 7.8 mg/kg of necrostatin-1 was intravenously administrated at the 1, 2, and 3 days after SCI. For necrostatin-1 group, necrostatin-1 was intravenously injected for three days. Basso Mouse Scale(BMS) score and standardized rump-height index were used to evaluate locomotor function at 1-, 3-, 5-, 7-, 10- and 14-day after injury. To observe cell apoptosis in injured cord, TUNEL staining was performed at 1-, 3-, 7-, and 14-day after injury. Western blot and immunohistochemical staining were performed to detect the expression of inducible nitric oxide synthase (iNOS), a classical marker of M1 type microglia/macrophage. Real time quantitative PCR was used to detect mRNA levels of TNF-α, interleukin-1β (IL-1β), IL-18, IL-4, IL-5, and IL-10. Results Necrostatin-1 significantly promoted the locomotor recovery in mice after SCI, reduced cell apoptosis around the SCI area; decreased the protein expression of M1 type microglia/macrophage marker iNOS and the number of iNOS-positive microglia/macrophage, and down-regulated the transcription levels of pro-inflammatory cytokines TNF-α, IL-18, and IL-1β, while promoting the transcription of anti-inflammatory cytokines IL-4, IL-5, and IL-10. Conclusion Necrostatin-1 significantly promotes locomotor function recovery after SCI in mice by reducing the number of apoptotic cells and inhibiting M1 microglia/macrophages-mediated pro-inflammatory factors.