Objective To provide an optimization method and a basic configuration for the configuration design of mandibular defect-repair implant. Methods A topology optimization computation based on density method was adopted to make topology optimization on reconstruction titanium plate for repairing mandibular defect. Results The effects of volume fraction F and penalization factor p on the optimized configuration were compared and analyzed, respectively, and the optimum parameters were chosen to be F=0.65 and p=3.5. Using this set of parameters, optimized computation was performed on the mandibular defect-repair implant, and the threeopening configuration was proved to be the basic optimization configuration. The result also showed that unilateral molar clenching had more significant effect on stress distributions in the implant as compared to incisal clenching. Conclusions A set of parameters suitable for optimizing configuration of mandibular defect-repair implant, as well as the basic configuration of optimized titanium plate were obtained, which could provide references for the design of mandibular defect-repair implant in clinic.