Abstract: Objective To evaluate and analyze the surgical features and clinical effects of free forearm flap and free posterior lateral perforator flap in maxillary tissue defect. Methods From April, 2013 to October, 2017, 24 cases of malignant tumors in the maxillary region were treated with oral and maxillofacial surgery in the first affiliated hospital of Bengbu medical college, including 13 cases of squamous cell carcinoma of the palate, 6 cases of adenoid cystic carcinoma of the palate, 4 cases of squamous cell carcinoma of the maxillary gingiva, and 1 case of squamous cell carcinoma of the maxillary sinus that had no invasion of the orbital floor. And 14 of them were repaired with forearm free flap immediately after operation. The area of the flap was 7 cm×8 cm and the smallest was 4 cm×5 cm. The rest 10 cases were repaired with the free posterior lateral perforator flap. The largest area of the flap was 13 cm×9 cm and the smallest was 5 cm×3 cm. The shape, swallowing function, voice function and prognosis of the two groups were evaluated after the operation. Results After operation, there were 22 cases of free flap survival in 24 patients in two groups and 1 case of vascular crisis after one day after operation. After two operations, 1 case had vascular crisis on three days after the operation, and the number of necrotic cases was still contradictory after the rescue. After the operation, the donor area and the operative incision were all healed at I stage. After operation, the recovery of the 24 cases, the swallowing and voice function were basically satisfactory, and there was no significant difference between the two groups. Conclusion The anatomical location of the free forearm flap is constant, the preparation is convenient, the pedicle of the blood vessel is long, the amount of cut and the length and width are flexible, the texture is soft and thin, the large soft tissue area can be provided, and the operation time can be saved by "double group operation". The posterior lateral perforator flap of the free leg has a large number of perforating vessels, a constant anatomical position, and thicker diameter of the tube, a good elastic wall, and a nerve graft with the nerve. The skin of the leg can be directly sutured. Two kinds of flaps can achieve satisfactory results in repairing maxillofacial tissue defects.