Objective To compare the effects of different fixation methods on stability of pediatric humeral proximal unstable fractures at different heights by using the finite element method. Methods Different pediatric humeral transverse fracture models at varying heights were created and fixed by elastic stable intramedullary nailing (ESIN) and Kirschner wire with different configurations. These models were imported into ANSYS 2019 to simulate seven working conditions, namely, the upper limb gravity, anterior flexion, posterior extension, adduction, extension, internal rotation and external rotation. The mean maximum displacement of the distal humerus and the mean maximum stress of the internal fixation were analyzed. Results The mean maximum displacement of the distal humerus was lowest in four-pin group at each height, while the average maximum stress on internal fixation was the smallest for ESIN at P1 and P4 heights. For P2 and P3 heights, the four-pin group had the lowest stress levels. Conclusions ESIN is superior to 3-pin fixation in lower fracture planes, while 4-pin Kirschner wires are more effective than ESIN at all heights.