Abstract: Objective To redesign the traditional circular external fixation structure to make it more suitable for intraarticular Pilon fracture fixation.the stability of the horseshoe annular external fixator was verified by analyzing the fracture displacement of the Pilon bone after fixation with the external fixator under load. Methods AO-C2 Pilon fracture model was prepared by pendulum saw according to the predetermined osteotomy line, and then fixed by horseshoe annular external fixator. the fixed ankle model was subjected to mechanical loading for axial loading. The axial force loading mode is from 0N to 150N, 300N and 450N successively .Dynamic capture instrument was used to record the displacement changes of fracture blocks in X (left and right), Y (upper and lower) and Z (front and rear) axes during 0-450N loading process. Results The overall left-right displacement of fibula ranged from 0.32mm to 0.70mm.The overall shift values range from -0.23mm to -0.27mm;The displacement range of the whole body before and after the fibula was 0.23mm-0.32mm, and the maximum difference was 0.09mm.The whole displacement value of the medial malleolus of the tibia was 0.02mm-0.14mm.The overall shift value amplitude in the upper and lower directions is -0.8mm -- -0.19mm;In the front and back direction, the overall shift value ranges from -0.13mm to -0.78mm.The global displacement of the lateral malleolus of the tibia was 0.05mm -- 0.07mm in the left and right directions. in the upper and lower direction, the overall shift value range is -0.03mm -- -0.36mm;In the anteriorly and anteriorly direction, the fracture fragment gradually shifted forward when the load increased from 300N to 450N, and the overall displacement value ranged from 0.27 mm to 0.47mm. Conclusion The horseshoe annular external fixator can not only stabilize the fracture end but also produce micromotion that is beneficial to fracture healing, which is in line with the biomechanical characteristics of fracture healing. the external fixation structure is simple, suitable for the treatment of Pilon fracture, and worthy of popularization and application.