Objective To investigate the effect of lateral femoral wall on PFNA internal fixation。Methods From January 2016 to June 2018, 124 cases of intertrochanteric fractures with complete follow-up data were collected and divided into group A (complete group) and group B (damaged group) according to whether the lateral wall was complete. Observed indicators: age, sex, degree of osteoporosis (singh index), postoperative TAD, cortical parallelism at the fracture end, incidence of delayed union of fracture, incidence of internal fixation failure and Harris score at the last follow-up. Results All patients were followed up until the fracture healed completely. There was no significant difference in age, sex, operation time, degree of osteoporosis and TAD between groups A and B (P > 0.05). In group B, the failure rate of internal fixation, the contraposition of distal and proximal cortex and the incidence of delayed union of fracture were all higher than those in group A. At the last follow-up, the excellent and good rate of Harris score was lower than that in group A, and the difference was statistically significant (P<0.05). Conclusion Intertrochanteric fracture of femur with irintergrity lateral wall belongs to unstable fracture, which is difficult to anatomically reduce in PFNA internal fixation, and is prone to loss of reduction, resulting in greater cortical contraposition, thus prolonging the healing time of fracture; moreover, due to the lack of stable support, there is a certain failure rate of internal fixation, which affects the functional recovery of hip joint and the effect of operation.