ObjectiveTo investigate the biomechanical influence of the oblique locking plate on the fixation of femoral shaft fracture. MethodsForty imitation artificial femur model with mechanical properties similar to human femur were selected and randomly divided into groups A, B, C, and D, 10 in each group; the femur fracture model was made by transverse osteotomy at 15 cm and 17 cm below the lesser trochanter of the femur and fixed with locking plate with 12 holes and cortical bone screws. The plate was placed in the middle of the longitudinal axis of the femur in group A, and was placed at 5, 10, and 15° angle axis in groups B, C, and D respectively. The axial compression, three-point bending, torsion tests were carried out to measure the strain. ResultsWith the compressive load and bending load increasing, the medial and lateral strains were significantly increased in each group (P<0.05); but no significant difference was found in strains under compressive load and bending load among 4 groups (P>0.05). With increasing torque, the strain was significantly increased in each group (P<0.05). At 10 N·m torque, there was no significant difference in the strain values among 4 groups (P>0.05); the strain value was significantly higher in groups C and D than groups A and B (P<0.05) and in group D than group C (P<0.05) at torque of 20 and 50 N·m, but no significant difference was found between groups A and B (P>0.05). ConclusionUnder different stress, the strain will be significantly increased when the plate is placed at >10° angle axis.