Abstract Objective To study the effect of different configurations of cannulated screws on the stability of arthroscopic ankle arthrodesis through finite element analysis.Methods A 37 year old volunteer who met the inclusion criteria was selected as the research object. Spiral CT scanning was performed from knee joint to plantar. DICOM images were obtained and imported into Mimics to segment the three-dimensional point cloud of calcaneus, talus, tibia and fibula. The finite element model of ankle joint was simulated in Geomagic and HyperMesh, including normal control model and three ankle joint arthrodesis models, Model A was Posteromedial + posterolateral parallel configuration , Model B was Posteromedial + anteromedial cross configuration, and Model C was Posteromedial + anterolateral + anterolateral configuration. The relative displacement of tibiotalar articular surface, the peak value of Mises stress and the average Mises stress were observed.Results Under plantar flexion, internal and external rotation loads, the average displacement of Model A was significantly greater than that of Model B and Model C (P < 0.001), but there was no significant difference between Model B and Model C (P > 0.05). The maximum displacement of ankle fusion model appeared in the anterior side of tibiotalar joint, in which Model A was the largest, followed by Model B and Model C. The mean Mises stress of Model A was significantly lower than that of Model B and Model C (P < 0.001), and there was no significant difference between Model B and Model C (P > 0.05). The peak stress of cannulated screw in Model A is greater than that of Model B and Model C. Conclusion the stability of the posteromedial + anteromedial cross placed configuration is better than the posteromedial + posterolateral parallel configuration, which is helpful to reduce the trauma of ankle fusion surgery under microscope.