[objective] To evaluate clinical efficacy of arthroscopic combined with calcium sulfate in the treatment of suppurative knee arthritis. [methods] A retrospective study was done in 9 patients with suppurative knee arthritis who underwent arthroscopic combined with calcium sulfate from January , 2017 to February, 2019 in our hospital. Of the 9 patients, 6 were male and 3 were female. All patients were a single knee joint disease. WBC, CRP, erythrocyte sedimentation rate (ESR), visual analog scale (VAS) score, knee joint function Lysholm score and Judet knee flexion score were compared at different follow-up times.[results] 9 patients were followed up for 10 to 24 months, with an average of 14.8 months. The Lysholm score and Judet knee flexion score were significantly higher than preoperative (P<0.05). The VAS score were significantly lower than preoperative (P<0.05). The CRP、ESR score were significantly lower than preoperative (P<0.05). [conclusion] Arthroscopic combined with calcium sulfate is an effective method，which can effectively improve the clinical symptoms and enhance the joint function