To investigate the relationship between the shape of the lateral wall and the early failure of internal fixation in the fracture of the femoral trochanteric region(FFT). Total 295 patients with femoral trochanteric fracture underwent internal fixation from January 2015 to January 2020 were selected. The patients were divided into two groups according to whether there was early internal fixation failure after surgery, 19 patients in the failure group and 276 patients in the normal group. Gender, affected side, age, AO classification, body mass index(BMI), preoperative hemoglobin, X-ray measurement of lower lateral wall thickness, preoperative internal diseases, intraoperative blood loss, postoperative tip apex distance(TAD), postoperative neck shaft angle, operation time and other data were compared between two groups. The shape of the lateral wall was compared between two groups, and the correlation between the shape of the lateral wall and the early internal fixation failure of femoral trochanteric fracture was analyzed. All patients were followed up for more than 1 year. There was no significant difference between two groups in terms of intraoperative blood loss, operation time, postoperative TAD, and postoperative neck shaft angle(P>0.05). At the latest follow-up, the visual anaglue scale (VAS) of the failure group was higher than that of the normal group(P<0.01), and the Harris score of the failure group was lower than that of normal group(P<0.05). The receiver operator characteristic (ROC) curve between shape of lateral wall and failure of early internal fixation of femoral trochanteric fracture was drawn. The critical value of the midpoint lateral wall thickness was 16.5 mm, and the area under the ROC curve was 0.845;The critical value of average sidewall thickness was 16.5 mm, and the area under ROC curve was 0.838;The critical value of the axial area of the sidewall was 7.5 mm, and the area under the ROC curve was 0.826. The shape of the lateral femoral wall measured by CT could be used as a predictive factor for the early failure of internal fixation of femoral trochanteric fractures. For patients at risk, more reasonable surgical plans and postoperative preventive measures should be developed.