Objective To investigate the clinical value of occlusal guide plate combined with intermaxillary fixation screw in mandibular defect repair with free fibular flap. Methods Between August and December 2011, 7 patients with mandibular tumor were treated, including 5 cases of ameloblastoma and 2 cases of gingival cancer. Of 7 patients, 4 were males and 3 were females, aged 32-65 years (median, 50 years). Occlusal guide plate was prepared and the implanted position of intermaxillary fixation screws was determined preoperatively. Hemimandibulectomy was performed in 5 cases, half mandibular segmental resection with condyle reservation in the other 2 cases. The free fibular flaps of 11-13 cm in length were harvested for repairing mandibular defects. When the free fibular flaps were fixed, the occlusal guide plate and intermaxillary fixation screws were utilized to restorate the occlusal relation. The donor site was sutured directly. Results The average operation time was 9.5 hours (range, 7-12 hours). All free fibular flaps survived completely. All incisions at the donor site and recipient site healed by first intention. All patients were followed up 10-14 months with an average of 12.3 months. All patients had symmetrical face, good occlusal relation, normal mouth opening, and normal mandibular lateral movement, and no pain of bilateral temporomandibular joints occurred. Panoramic tomography showed good mandibular contour and the suitable emplacement of fibular flaps postoperatively. No tumor recurrence occurred during follow-up period. Conclusion When repairing the mandibular defect with free fibular flap, occlusal guide plate with intermaxillary fixation screw contributes to simplifying operation, accurate recovery of the appearance and occlusal relation, and improving the oral comfort level postoperatively.