To observe the intervention effect of Huoxue ointment on the motor function of osteoarthritis rats, and to evaluate its effect on the ultrastructure of articular cartilage and the expression of Wnt/β-catenin signaling pathway. Methods:A total of 30 SD rats were randomly divided into blank group, model group and Huoxue ointment group, with 10 rats in each group. The model group and Huoxue plaster group were treated with intra-articular injection of 4% papain to replicate the osteoarthritis model, then Huoxue ointment group were treated with external application of Huoxue ointment, intervention for 14 consecutive days. Rat articular subchondral bone tissue morphology, cartilage morphology and cartilage tissue Wnt-2, beta-catenin of three groups were compared. Results:1) The activity of the knee joint in the model rats was significantly lower than that in the blank group, and the motion range of the knee joints in Huoxue ointment group was greater than that in the model group. The difference was statistically significant (P<0.05). 2) The trabecular bone showed obvious hardening phenomenon in the model group. There were local fractures. The trabecular arrangement was disorder. The formation of osteophyte was observed. The bone trabecular arrangement in Huoxue ointment group was significantly more than that in the model group, and the fracture phenomenon was significantly reduced. BS/BV of rats with model establishment elevated significantly compared with control group, and Tb.Th and Tb.N were lower than that in blank group. The huoxue ointment group improved compared with the model group, and the differences were statistically significant (P<0.05). 3) HE staining showed that the rats in cartilage matrix of the blank group had normal morphology, and uniform coloring was normal with visible and clear tide line. The cartilage in model group showed different degrees of fibrosis, and the number of cartilage cells was decreased. The tidal line was blurred; Chondrocytes of Huoxue ointment group increased in comparison with the model group, and part of the tidal line was visible. 4) Western Blot test showed that the Wnt-2 and β-catenin levels of cartilage tissue in model group were significantly higher than those in blank group, while Huoxue ointment group was higher than that in blank group. It was significantly lower than that in model group, and the difference was statistically significant (P<0.05). Conclusion:Huoxue ointment can protect cartilage and subchondral bone in osteoarthritis rats, and its mechanism may be related to inhibiting the expression of Wnt/β-catenin signaling pathway.