Objective To explore the effect of botulinum toxin type A (BTX-A) injection combined with facial expression muscle training on facial synkinesis grading in patients with sequelae of facial paralysis. Methods A total of 50 patients with sequelae of facial paralysis admitted to the Department of Neurology, Yanji City Hospital from January 2024 to January 2025 were selected. According to different treatment schemes, they were divided into the control group and the observation group, with 25 patients in each group. The control group was treated with facial expression muscle training alone, and the observation group was treated with BTX-A injection combined with facial expression muscle training on the basis of the control group's regimen. The facial synkinesis grading, Sunnybrook facial nerve function score and facial symmetry indexes were compared between the two groups. Results After treatment, the proportions of patients with grade 0 and grade Ⅰ facial synkinesis in the observation group were 36.00% and 48.00%, respectively, which were higher than 8.00% and 16.00% in the control group (P<0.05). After treatment, the Sunnybrook facial nerve function scores and total score of the observation group were better than those of the control group (P<0.05). After treatment, the facial symmetry index of the observation group was higher than that of the control group (P<0.05). Conclusion Compared with facial expression muscle training alone, BTX-A injection combined with facial expression muscle training can effectively reduce the degree of facial synkinesis in patients with sequelae of facial paralysis, improve facial symmetry, and enhance the quality of facial nerve function recovery.