Objective To investigate the clinical effect of high head and neck window bone grafting via DDA in the treatment of femoral head necrosis in "peri-collapse stage".Methods From September 2015 to March 2018, 32 patients (37 hips) with femoral head necrosis in the "peri-collapse stage" were retrospectively analyzed, with 24 hips in ARCO stage II, 8 hips in ARCO stage IIIA and 5 hips in ARCO stage IIIB.Preoperative orthopedic and frog position radiographs of the pelvis, CT and MRI of the hip joint were taken to evaluate the collapse and extent of the necrotic area and the weight-bearing area.In all cases, DAA approach was used to expose the head and neck, a high window was opened with part of cartilage to remove the necrotic bone, and autogenous iliac crest was used to press the bone graft.The success rate of hip preservation was evaluated according to Harris score, hip pain score and flexion activity.Results All the patients (37 hips) were followed up. The Harris score increased from (65.5±8.87) to (87.28±6.81), and the hip pain score increased from (28.59±4.91) to (39.88±4.43).The mean flexion activity of hip joint increased from (75.94±5.74) ° to (96.56±10.58) °, which was statistically significant.Twenty-seven patients (29 hips) were successfully protected, and the success rate was 84.4%.Conclusion Accurate evaluation of "peri-collapse stage" is the key to hip preservation for femoral head necrosis. Minimally invasive exposure of anterolateral femoral head through DAA approach, high head and neck window is closer to the necrotic area, and the removal of dead bone is more complete, which can improve the success rate of hip preservation.