Objective To establish a finite element model of canine segmental mandibular reconstruction by partial- cortical-cutting distraction osteogenesis. Methods The geometry model was established by Mimics software via reading the data of DICOM format from CT and was cut with Magics software. The finite element model was established and was analyzed by MARC software. Results A finite element model of canine segmental mandibular reconstruction by partial -cortical -cutting distraction osteogenesis was established. The model was composed of five parts. These five parts were felted via Magics software. The Von Mises stress of the joint region of slice and the slide segment were 34.60 MPa when the slide segment was retained 1.4 mm width during distraction osteogenesis with the force of 12 N. Conclusion The biomechanics analysis can be complated through the finite element model of canine segmental mandibular reconstruction by distraction osteogenesis that retains lingual cortical bone.