Objective To explore the effect of ozone water acupoint injection combined intra-articular irrigation on pain and related factors in the patients with knee osteoarthritis(KOA).Methods Sixty-four eld-erly patients with KOA in the Third Affiliated Hospital of Henan University of Traditional Chinese Medicine from June to December 2023 were selected as the study subjects and divided into the observation group and control group by adopting the random number table method,32 cases in each group.The control group adopt-ed the ozone water acupoint injection,and the observation group was combined with ozone water intra-articu-lar irrigation on the basis of the control group.The both groups were treated once a week for 4 consecutive weeks.The Visual Analogue Scale(VAS)score,Lysholm knee function score,clinical effect and the levels of joint fluid PGE2,IL-1β and IL-6 before and after treatment were compared between the two groups.Results The VAS score,Lysholm knee function score and the levels of PGE2,IL-1β and IL-6 levels after treatment in the two groups were significantly improved compared with before treatment(P＜0.05),moreo-ver the improvement in the observation group was more significant than that in the control group(P＜0.05).The multiple linear regression analysis showed that the VAS score before treatment was related with the PGE2 level(P＜0.05)and had no relation with the age and level of IL-6 and IL-1β(P＜0.05).The total ex-cellence and good rate in the observation group was significantly higher than that in the control group(P＜0.05).The no adverse reactions such as fainting during acupuncture treatment,skin infection at injection site,symptom increase and joint discomfort appeared during the treatment process.Conclusion The ozone water acupoint injection combined intra-articular irrigation in treating KOA has better effect,which may improve the pain symptom by regulating the induced pain factors and inflammatory factors levels.