Objective To investigate the effect of esketamine on the activation of astrocytes in the spinal dorsal horn of chronic pain mice and to analyze its impact on the Wnt/β-catenin signaling pathway. Methods Forty C57BL/6J mice were selected and randomly divided into five groups: sham surgery group (sham group), pain model group (model group), low-dose ketamine group (L-Es group), medium dose ketamine group (M-Es group), and high-dose ketamine group (H-Es group). Except for the sham group, all other groups used the sciatic nerve branch selective injury method to establish chronic pain mouse models. Each group received corresponding drug treatment and their Mechanical Withdrawal Threshold (MWT) and Thermal Withdrawal Latency (TWL) were measured. In addition, the expression level of glial fibrillar acidic protein (GFAP) in the spinal cord was detected by immunohistochemical methods; Using immunofluorescence technology to observe the activation of astrocytes in the dorsal horn of the mouse spinal cord; Use enzyme-linked immunosorbent assay (ELISA) to detect the levels of inflammatory factors interleukin-1 β (IL-1 β), interleukin-6 (IL-6), and tumor necrosis factor - α (TNF - α) in the spinal cord; Real time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze the mRNA expression levels of Wnt3a, β - catenin, and Cyclin D1 in mouse spinal cord; Evaluate the expression of Wnt3a, β - catenin, and Cyclin D1 proteins in mouse spinal cord using Western blot (WB). Results Compared with the sham group, the MWT and TWL of the Model group mice were significantly reduced (both P<0.001); At the same time, the levels of inflammatory factors IL-1 β, IL-6, TNF - α, and the expression level of GFAP protein all increased (all P<0.001), and there was a co expression phenomenon between GFAP and Iba-1. The mRNA and protein expression of Wnt3a, β - catenin, and Cyclin D1 also significantly increased (all P<0.001). Compared with the Model group, the MWT and TWL of mice in each dose group of ketamine were significantly increased (all P<0.05), while the levels of inflammatory factors IL-1 β, IL-6, and TNF - α, as well as the expression of GFAP protein, were significantly decreased (P<0.05). There was no co expression of GFAP and Iba-1, and the mRNA and protein expression of Wnt3a, β - catenin, and Cyclin D1 were significantly decreased (P<0.05). Conclusion Esketamine can inhibit the activation of astrocytes and inflammatory response, thereby reducing chronic pain. The mechanism may be closely related to the regulation of Wnt / β-catenin signaling pathway.