Objective To study the fracture mechanism of calcaneus. Methods To analyze the stresses in calcaneus by using bending strength theory, shearing strength theory and main main stress theory in mechanics of materials, to study the shocking loads of calcaneus by using momentum principle, and to determine the destructive load of calcaneus through the static pressing experiment.Results The part in calcaneus around the wedged cave was the weakest part; the destructive load of calcaneus was about 24 times of the body weight; when a person jumped down from the height 1.5 meters to the ground, the shocking loads acted on the calcaneus were 36 times of the per son's weight. Conclusion When a person jumped down from a high place and his heel contacted the ground first, the shocking loads acted on the calcaneus could be very large; in addition, the initial velocity of the person had a great influence on the shocking loads acted on the calcaneus.