Objective To investigate the short-term effectiveness of reconstruction plate internal fixation via improved Stoppa approach combined with iliac fossa approach and Kocher-Langenbeck approach for complex acetabular fractures. Methods Between January 2015 and January 2020, 30 patients with complex acetabular fractures were treated with reconstruction plate internal fixation via improved Stoppa approach combined with iliac fossa approach and Kocher-Langenbeck approach. There were 20 males and 10 females with an average age of 52.1 years (range, 25-71 years). The cause of injury included traffic accident in 17 cases and falling from height in 13 cases. Among them, 14 cases were left acetabular fractures and 16 cases were right acetabular fractures. According to Letournel classification, there were 16 cases of double column fractures, 2 cases of transverse fracture with posterior wall fracture, 4 cases of anterior column and posterior hemi-transverse fractures, 8 cases of T-shaped fracture. The displacement distance of fracture ranged from 6 to 30 mm (mean, 11.6 mm). The time from injury to operation was 6-14 days (mean, 8.7 days). Results The operation time was 2.0-4.5 hours (mean, 3.0 hours). The intraoperative blood loss was 200-800 mL (mean, 450.0 mL). All patients were treated with autologous blood transfusion during operation. All incisions healed by first intention after operation, and no infection occurred. All patients were followed up 12-15 months (mean, 13.4 months). The drainage tube was removed at 2-3 days after operation. After extubation, X-ray film and three-dimensional CT were performed to recheck the fracture reduction. According to Matta score system, 20 cases were excellent, 5 were good, and 5 were poor, the excellent and good rate was 83.3%. All fractures healed with the healing time of 16-25 weeks (mean, 17.7 weeks). According to Merle d’Aubigne-Postel score system, the hip function at 1 year after operation was rated as excellent in 18 cases, good in 6 cases, and fair in 6 cases, and the excellent and good rate was 80.0%. Two cases suffered from sciatic nerve injury due to traction during operation, 7 cases had heterotopic ossification, 2 cases had traumatic hip arthritis, and no other complications occurred. Conclusion For complex acetabular fractures, the reconstruction plate internal fixation via improved Stoppa approach combined with iliac fossa approach and Kocher-Langenbeck approach can obtain good short-term effectiveness with good reduction and hip joint function, and less complications.