In this paper,the effect and mechanism of helicid on pain in rats with knee osteoarthritis are studied.The basic pain threshold is measured after adaptive feeding of SD rats,and unqualified rats are eliminated accordingly.According to the basic pain threshold,SD rats are randomly divided into blank group,model group,sham operation group and administration group.The KOA model is induced by injecting MIA into the right knee joint of rats.The pain threshold and joint diameter are measured regularly.After 14 days of model establishment,the number and fluorescence intensity of tyrosine kinase A (TrkA) and transient receptor potential vanilloid subfamily member 1 (TRPV1) positive cells in dorsal root ganglia (DRG) are measured.Compared with the model group,helicid can significantly improve the thermal and mechanical pain sensitivity induced by MIA.The TrkA immunofluorescence intensity and the number of TRPV1 positive cells in L4DRG of the administration group were lower than the model group.The results show that helicid can alleviate the pain of KOA in rats,the mechanism of which is related to the inhibition of TrkA-TRPV1 pathway in L4DRG.