Objective：To observe the clinical effect of Baihuadan analgesic spray for knee osteoarthritis(KOA).Methods：Selected 100 cases of patients with KOA，and divided theminto the treatment group and the control group randomly，50 cases in each group.The treatment group was given basic treatment combined with spraying Baihuadan analgesic spray externally on affected knee，while the control group was given basic treatment combined with external application of diclofenac diethy lamine emulgel on affected knee.Compared the comprehensive therapeutic effect in the two groups，and observed the changes of visual analogue scores(VAS)，Lequesne indexes and scores of the SF-36 questionnaire before and after treatment.Results：The total effective rate was 90.0%in the treatment group and 72.0%in the control group，the difference being significant(P ＜ 0.05).After treatment，both VAS score and Lequesne index in the two groups were decreased when compared with those before treatment( P ＜0.05).The VAS score and Lequesne index in the treatment group were lower than those in the controlgroup(P ＜ 0.05).After treatment，scores of physical functioning(PF)，role-physical(RP)，bodily pain(BP)，general health(GH)，social functioning(SF)，vitality(VT)，role-emotional(RE)and mental health(MH)in the two groups were all increased when compared with those before treatment(P ＜ 0.05).The scores of PF，RP，BP，GH，VT，SF and RE in the treatment group were increased more obviously than those in the controlgroup( P ＜0.05).No significant difference was found in the comparison of the score of MH in the two groups(P＞0.05).No adverse reaction was found in the two groups during treatment.Conclusion：Baihuadan analgesic spray has clear therapeutic effect in treating KOA，which can improve the quality of life of patients.