Objective To investigate the optimal scheme about the external loading of resetting tensile stress for clavicular fractures, so as to provide some mechanical references for optimal design of external fixators for clavicular fractures. Methods The shoulder CT scanning data from a volunteer were used to establish the three-dimensional model of human left shoulder by Mimics software. In order to better simulate the actual human shoulder, the ligament tissues were added in the model and the constraints of muscles were considered, and the experimental model for simulation analysis on resetting tensile stress was established. By 3 simulation experiments, the impacts from directions of resetting tensile stress, positions of action points and value ranges were simulated and analyzed, respectively. The resetting tensile stresses obtained from clavicle of the shoulder model under various external loading cases were simulated by orthogonal test methods. Results When the (angle between the horizontal plane projection of shoulder force which was loaded by external fixator and the coronal axis ) was greater than 45°, clavicle could obtain the resetting tensile stress, which became greater with the angle increasing. When (angle between the sagittal plane projection of shoulder force which was loaded by external fixator and the sagittal axis) was 30°-45°, the resetting tensile stress of clavicle was the maximum. The farther the position on which the loads from external fixator was exerted from the horizontal position of clavicle, the larger the resetting tensile stress of clavicle was. Conclusions The results of orthogonal test show that the optimal resetting tensile stress is produced with parameter combination of θ=65°, η=50°, acting on the center of humerus head of the shoulder