Spinal cord injury (SCI) inflicts terrifying consequences, which can cause permanent paralysis. During acute SCI, the damaged tissue undergoes pathological processes such as ischemia, hypoxia, and edema, simultaneously causing a significant accumulation of reactive oxygen species (ROS) in the injured spinal cord. The continuous accumulation of ROS destroys cell integrity, promotes the secretion of proinflammatory factors, and further exacerbates edema and necrosis in the damaged spinal cord tissue, ultimately leading to neuronal apoptosis and failure of axon regeneration. Therefore, it is crucial to combat oxidative stress following SCI. In our study, we utilized environmentally friendly methods to extract Onion exosomes (Onion-ex), which inherit onions' antioxidant, anti-inflammatory, and neuroprotective properties of onions. Surprisingly, we observed that Onion-ex had an unexpected positive impact on functional recovery following SCI. Furthermore, our findings indicate that the antioxidative stress mechanism of Onion-ex depends on the KEAP1/NRF2/ARE signaling pathway. Onion-ex's remarkable therapeutic effects and biological safety provide valuable insights for clinical treatment involving plant-derived exosomes.