Abstract: [Objective] To explore the clinical effect of debridement,antibiotics and implant retention(DAIR) combined with ?irrigation-drainage in the treatment of acute periprosthetic knee joint infection(PKJI).[Methods] The clinical data of 21 patients (21 knees) with acute PKJI treated with DAIR combined with ?irrigation-drainage in our hospital from January 2012 to September 2020 were retrospectively analyzed,including 7 males and 14 females.Cases;age 50-79 years,average (64.0 ± 8.2) years old,compare the changes of laboratory indicators during admission and last follow-up;preoperative and postoperative VAS scores,knee HSS scores,and infection cure rates,and recheck both lower extremity color Doppler ultrasound and X-ray film.[Results] All 21 patients were followed up for 9-108 months.The ESR (15.3±8.6)mm/h,CRP (0.82±1.55)mg/dL,IL-6 (2.62±1.83)pg/ml of the patients at the last follow-up were significantly lower than those at admission,the difference was statistically significant (P<0.05);the postoperative VAS score (1.5±0.7),the knee HSS score (86.7±5.0) was significantly improved compared with that before operation,and the difference was statistically significant (P<0.05).Fifteen cases (71.43%) were cured of infection, and 6 cases (28.57%) recovered well after the second-stage revision surgery after the infection recurred.[Conclusion] DAIR combined with drip and drainage can effectively control infection and retain good joint function in the treatment of acute PKJI.