Objective To investigate the effect of arthroscopic debridement and meniscectomy in treatment of moderate or severe meniscus injury combined with knee osteoarthritis in early or middle stage. Methods 156 cases diagnosed with moderate or severe meniscus injury combined with knee osteoarthritis in early or middle stage were collected from October 2011 to October 2014. Lysholm knee score and preoperative examinations such as anteroposterior, lateral, axial radiographs, the standing full leg length X-ray film and MRI scan of the knee were recommended to definitively understand the osteoarthritis staging and meniscus injury grading. All patients were treated with arthroscopic debridement and meniscectomy. After operation, physical rehabilitation exercises and regular clinical follow-up were carried out as planned. The Lysholm knee score data from preoperation and terminal follow-up was statistical analyzed. Results No patient experienced any perioperative and postoperative complications. Statistical analysis showed that the Lysholm knee score of postoperation was significantly higher than that of preoperation [(87.3 ± 7.9) vs (67.5 ± 4.9), P < 0.05). Conclusion Arthroscopic debridement and meniscectomy in treatment of moderate or severe meniscus injury combined with knee osteoarthritis in early or middle stage, gains beneficial effects for its minimal invasion and quick recovery.