To investigate the therapeutic effects of quercetin (QR)-loaded polycaprolactone-polyglycol triblock (PECT) thermosensitive hydrogel in a rat model of spinal cord injury (SCI). Methods: The thermosensitive hydrogel with QR-PECT was prepared to release quercetin at 37 ℃. The thermosensitive and rheological properties of the hydrogel were characterized. Cell compatibility of the hydrogel was assessed using the CCK-8 assay. The free radical scavenging ability of the hydrogel was evaluated using the 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging assay. The ability of the hydrogel to scavenge intracellular reactive oxygen species (ROS) was evaluated using a ROS detection kit. A rat model of SCI was established and divided into four groups: sham, SCI, QR, and QR-PECT hydrogel. The BBB score was used to evaluate the recovery of motor function in the rats. Neuronal migration and infiltration were examined using Nissl staining, and biocompatibility of the hydrogel was assessed by H&E staining. Results: The prepared QR-PECT polymer formed a hydrogel at 37 ℃ and continuously released QR. CCK-8 assay results showed that the cell viability in the QR-PECT hydrogel group was comparable to that of the SCI group. DPPH clearance assays revealed a 60% scavenging rate in the QR-PECT hydrogel group, which was comparable to that of the QR group. ROS fluorescence intensity in HT22 cells indicated a significant reduction after treatment with the QR-PECT hydrogel. Eight weeks after SCI, significant motor function recovery was observed in the QR-PECT hydrogel group, with substantial neuronal infiltration confirmed by Nissl staining. H&E staining revealed no significant differences among heart, liver, spleen, lung, and kidney samples from the normal and QR-PECT hydrogel groups. Conclusion: The QR-PECT hydrogel demonstrated superior biocompatibility and antioxidant characteristics, promoting neuronal regeneration and enhancing motor function recovery in SCI rats.