To compare the effectiveness of proximal femoral nail anti-rotation (PFNA) combined with minimally invasive percutaneous plate osteosynthesis (MIPPO) and Intertan intramedullary nail fixation by closed reduction in the treatment of AO/Orthopaedic Trauma Association (AO/OTA) type 31-A3.3 intertrochanteric fracture with incomplete lateral wall. The clinical data of 54 patients with AO/OTA type 31-A3.3 intertrochanteric fracture who met the selection criteria and were admitted between January 2012 and January 2018 were retrospectively analyzed. According to different surgical methods, the patients were divided into group A (24 cases with lateral wall reconstruction by MIPPO combined with PFNA internal fixation) and group B (30 cases with Intertan intramedullary nail fixation by closed reduction only). There was no significant difference between the two groups ( P>0.05) in terms of gender, age, side of injury, cause of injury, and combined medical diseases. The operation time, intraoperative blood loss, time to weight-bearing, fracture healing time, and postoperative complications were recorded and compared between the two groups. The tip apex distance (TAD) was measured at 2 days, 2 months, and 1 year after operation. At 12 months after operation, the hip joint function was evaluated according to Harris scoring standard, and the rate of conformity (Harris score were more than 70) was calculated. The wounds of the two groups healed by first intention, without infection, skin deformity, and other incision complications. The operation time and intraoperative blood loss of group A were significantly more than those of group B, and the time to weight-bearing and fracture healing were significantly shorter than those of group B ( P<0.05). The patients were followed up 9-20 months (mean, 14.7 months) in group A and 9-19 months (mean, 13.8 months) in group B. There was no significant difference in TAD values at 2 days, 2 months, and 1 year after operation between the two groups ( P<0.05), and there was also no significant difference in TAD values between the postoperative time points ( P>0.05). There was 1 case of infection, 1 case of screw withdrawal, 2 cases of screw removal, and 1 case of bone nonunion in group B, the incidence of complications was 16.7%; there was only 1 case of screw withdrawal combined with screw blade withdrawal in group A, the incidence of complications was 4.2%; there was no significant difference between the two groups ( χ 2=2.109, P=0.146). At 12 months after operation, the Harris scores of pain, function, malunion, range of motion, and total score in group A were significantly better than those in group B ( P<0.05). The rate of conformity of group A was 95.83% (23/24) and 76.67% (23/30) in group B, and the difference between the two groups was significant ( χ 2=3.881, P=0.049). For the AO/OTA type 31-A3.3 intertrochanteric fracture with incomplete lateral wall, compared with the closed reduction Intertan intramedullary nail fixation, the incidence of internal fixation failure after MIPPO reconstruction with lateral wall combined with PFNA fixation was lower, the time to weight-bearing was earlier, and the postoperative function was better.