Objective To study the effect of interlocking intramedullary nail on transverse olecranon fracture. Methods Using experimental methods, nine pairs of fresh ulna specimens were collected and the transverse fracture model of olecranon was established. Kirschner wire tension band and interlocking intramedullary nail were used to repair the fracture. Cyclic dynamic tension loads with amplitude of 25N, mean value of 45N and frequency of 0.5Hz were applied to the triceps tendon under simulated elbow flexion conditions of 30°, 45° and 60°, respectively. The fracture displacement data of specimens were recorded in three groups in 300 cycles. Results The data has been analyzed, and the data of a single period was recorded at an interval of 100 periods from the first period in the same group of data. The two-sample heteroscedasticity T-test of two-tailed distribution was adopted. The fracture displacement of the 30° interlocking intramedullary nail group was (1.831±0.333) mm, and that of the 30° Kirschner wire tension band group was (3.723±2.390) mm, with a P value of 0.024. The fracture displacement of 45° interlocking intramedullary nail group was (1.167±0.374) mm, and that of 45° Kirschner wire tension band group was (2.455±0.609) mm, P = 0. The fracture displacement of the 60° interlocking intramedullary nail group was (1.407±0.342) mm, and that of the 60° Kirschner wire tension band group was (3.112±1.025) mm, P = 0. The fracture displacement of interlocking intramedullary nail was smaller. Conclusion The mechanical properties of interlocking intramedullary nail are better than those of Kirschner wire tension band, and the interlocking intramedullary nail is more stable and firmer in the fixation of transverse olecranon fracture. Moreover, the interlocking intramedullary nail was installed with the operating tool, which made the operation more accurate and faster, and the operation efficiency was greatly improved.