Submental island flap has certain advantages in repairing postoperative defects of oral cancer, and it can often achieve similar or even better effects compared with those of the free tissue flap. In this study, according to the different characteristics of patients and postoperative defects of oral cancer, submental island flaps with different states of vascular pedicle were prepared, and its repair methods, safety, and clinical effects in treating postoperative defects of oral cancer were investigated. 83 patients with oral cancer who met the inclusion criteria were selected. According to the different characteristics of the patients and postoperative defects of oral cancer, the traditional submental island flap vascular pedicle was modified into three different states: submental artery perforator flap, vascular pedicled flap with the anterior belly of digastric muscle but without the submandibular gland (SIF with anterior belly of DM), and vascular pedicled flap with the anterior belly of the digastric muscle and the submandibular gland (SIF with anterior belly of DM and SG). The types of the submental artery and the drainage vein, flap survival, and complications, were observed. The flap was successfully harvested for all patients, and the submental artery could be found or separated for all of them, with the venous drainage to the internal jugular vein in 57 (57/83, 68.67%), to the external jugular vein in 18 (18/83, 21.69%), and to the anterior jugular vein in eight (8/83, 9.64%) cases. Submental artery perforator flap was used for 11 cases, complete necrosis occurred in two cases (2/11, 18.18%), partial necrosis occurred in one case (1/11, 9.09%); SIF with anterior belly of DM was used for 49 cases, complete necrosis occurred in one case (1/49, 2.04%), partial necrosis occurred in four cases (4/49, 8.16%); SIF with anterior belly of DM and SG was used for 23 cases, including chimeric flap combining the submental island flap and the submandibular gland used for 15 cases, there were no cases of complete or partial necrosis. Submental island flap was effective in repairing postoperative defects of oral cancer. Submental island flaps with three different states of vascular pedicle could repair oral cancer-affected tissues with different defect characteristics.