Objective To explore the effectiveness of muscle energy technique (MET) in shoulder and neck functional exercise after cervical lymph node dissection for oral cancer patients, and to promote postoperative shoulder and neck function recovery. Methods A total of 102 oral cancer patients who underwent cervical lymph node dissection were randomized to one of two groups, with 51 in each group. The control group received conventional active range-of-motion (ROM) exercises, while the intervention group received shoulder and neck functional exercises based on MET. ROM of the neck and the shoulder, the Constant-Murley scores, and the Shoulder Pain and Disability Index (SPADI) scores were compared between the two groups preoperatively and at 1 day, 1 week, and 2 weeks postoperatively. Results After the intervention, the intervention group showed significantly better neck ROM and shoulder ROM, the Constant-Murley scores, and the SPADI scores than the control group (intervention, time, and interaction effects all P＜0.05). Conclusion Shoulder and neck functional exercises based on MET can effectively improve neck and shoulder mobility and shoulder function, and relieve shoulder pain and dysfunction in oral cancer patients after cervical lymph node dissection.