Objective To review the progress of knee-salvage treatment based on the step therapy idea for knee osteoarthritis (KOA). Methods The domestic and foreign literature in recent years was searched, and the treatments of KOA at different stages were summarized and analyzed. Results The treatment of KOA is aimed at alleviating symptoms, delaying structural changes of joints, maintaining joint function, and improving quality of life. So the conservative treatment is still the first choice for KOA at early stage. Arthroscopic surgery can assist in the diagnosis and classification, simultaneously remove the intra-articular irritants, and limitedly repair the cartilage. Osteotomy is suitable for the KOA with abnormal lower extremity weight bearing line and articular line. And it can effectively balance the weight bearing stress of knee joint, improve the clinical symptom, and alleviate the progression of disease. Joint distraction can improve the mechanical environment of knee joint and repair the defect cartilage partly. With the technical development, unicompartmental knee arthroplasty (UKA) is back in fashion in recent years. It is a kind of real joint surface replacement, which is an important means of knee preservation method in patients with anterior medial KOA. Conclusion At present, there are many knee-salvage treatments based on the severity of the disease. Osteotomy and UKA are the most widely used and successful surgical techniques for knee preservation. However, the indications should be properly selected, and the surgeon should accumulate enough clinical experience. Otherwise, it is difficult to achieve good results.