Objective To compare the degree of pain between invisible orthodontic treatment without brackets and selfligating bracket in the initial stage of orthodontic treatment. Methods A total of 50 patients who received orthodontic treatment in the Department of Stomatology of Guigang People's Hospital from April 2019 to December 2022 were randomly divided into control group and study group. The control group was treated with self-ligating brackets, and the study group was treated with invisible orthodontic treatment without brackets. The pain degree and ulcer occurrence at 4 h, 12 h, 24 h, 3 d, 5 d and 7 d after treatment were compared between the two groups. Results Pain occurred in both groups after treatment, peaked at 12-24 h, and gradually decreased after 3 d. The pain intensity of the study group was lower than that of the control group at 6 time periods, and the difference was statistically significant ( P <0.05). The incidence of ulcer in the study group was lower than that in the control group, and the difference was statistically significant ( P <0.05). Conclusion In the initial stage of orthodontic treatment, both appliances will produce pain and discomfort, but the incidence of pain and ulcer in patients with invisible orthodontic treatment without brackets is lower.