Objective To conduct an epidiiological investigation of clustered surgical site infection (SSI) after arthroscopic surgery in orthopedic ward, and provide evidence for the prevention and control of healthcare-associated infection (HAI). Methods Epidiiological investigation was carried out on 3 cases of SSI after arthroscopic surgery in the orthopedics department of a tertiary hospital from Septiber to October 2020. Evidence-based intervention was performed. Prevention and control effect was evaluated. Results There were 3 cases of SSI after arthroscopic surgery in the orthopedic ward in a short time. Pseudomonas aeruginosa (P. aeruginosa) was isolated from incision secretion culture, and drug sensitivity spectrum phenotypes of isolated strains were identical. Arthroscopic surgery was suspended. Multiple sampling was conducted on hands of the relevant medical staff, ward environment, and surgical instruments. P. aeruginosa was isolated from flushing fluid specimen of arthroscopic trocar by simulating surgical operation, and corresponding drug sensitivity results were consistent with P. aeruginosa isolated from the patient's incision secretion. Intervention was carried out according to epidiiological investigation results. Low tiperature plasma sterilization on trocar was changed into high tiperature and pressure sterilization. Specimens of lumen flushing fluid were collected and cultured by simulating the arthroscopic surgery again, and no P. aeruginosa was detected. One month after the resumption of arthroscopic surgery, no SSI case was found, thus confirmed the effectiveness of the prevention and control measures. Conclusion Biofilm may form in the lumen of the arthroscopic trocar, which is difficult to riove during cleaning. Low tiperature plasma sterilization can not penetrate the biofilm, resulting in clustered SSI event of arthroscopic operation. Thermodynamic sterilization method can effectively sterilize the pathogenic bacteria in biofilm.