Objective To study the effectiveness of CFEFD, on the treatment of calcaneal fracture to provide the reliable theoretical basis for clinical operations. Methods Seven fresh specimens of adult lower limb heels were collected for experimental stress analysis to establish experimental mechanics modeling. To compare the biomechanical properties between the normal human calcaneus heel bones and those of calcaneal fracture, by using CFEFD. Results The experimental results show that there is no significant difference (P>0.05) in biomechanical properties, bearing capacity, stress of calcaneus heel bones, displacement of instep, and other aspects for posterior bones between the calcaneal fracture with the adjustable external fixation device and the normal human calcaneus heel bones. The rigidity of this device is found to satisfy the design requirements. Conclusion This device is not only able to satisfy the biomechanical requirements for calcaneus heel bones with its endurable strength, strong bearing capacity and favorable reliability in the treatment of calcaneal fracture, but also safe and easy to use, and proves to be one of the best medical apparatuses deserving the popularization in the medical applications.