Abstract: OBJECTIVE To explore the curative effect of postoperative continuous irrigation and drainage on acute suppurative arthritis in the patients undergoing arthroscopic knee joint debridement and observe the influence on prognosis so as to provide guidance for treatment of acute suppurative arthritis. METHODS A total of 102 patients who were hospitalized for treatment in the Affiliated Hospital of Binzhou Medical College due to acute suppurative arthritis from Jan 2019 to Jun 2021 were enrolled in the study and were divided into the study group with 52 cases and the control group with 50 cases according to the therapeutic schedules, and the clinical data of the enrolled patients were retrospectively analyzed. The study group was treated with continuous irrigation and drainage after the arthroscopic surgery, while the control group was simply given arthroscopic debridement. The postoperative inflammatory indexes, visual analogue scale (VAS) score and knee joint function were compared between the two groups. RESULTS The joint fluid specimens were cultured positive in 86 patients; totally 86 strains of pathogens were isolated, 55.81% of which were gram-positive bacteria, and 44.19% were gram-negative bacteria. Staphylococcus aureus and Staphylococcus epidermidis were the predominant species of the gram-positive bacteria; Escherichia coli and Acinetobacter baumannii were dominant among the gram-negative bacteria. The levels of D-dimer, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and procalcitonin (PCT) of the two groups were lower after the surgery for 3 and 14 days than before the surgery, and the levels of above indexes of the study group were lower than those of the control group(P＜0.05).The postoperative follow-up showed that the symptoms of pain and knee joint function were improved more remarkably in the study group than in the control group(P＜0.05); the excellent and good rate of knee flexion range of motion was 86.54%(45/52) in the study group, higher than 60.00% (30/50) in the control group, and there was significant difference between the two groups(χ²＝9.224,P＝0.002). CONCLUSION The postoperative continuous irrigation and drainage can remarkably alleviate the pain of the patients undergoing arthroscopic knee joint debridement in early stage and improve the knee joint function as well as the knee flexion range of motion, and it is worthy to be promoted in the hospital.