Objective To explore the clinical effect of Twin-block appliance in the treatment of angle class Ⅱ malocclusion. Methods A total of 50 patients with angle class Ⅱ malocclusion admitted to our hospital from April 2020 to May 2022 were selected as the research objects and divided into control group and study group by random number table method, with 25 patients in each group. The control group was treated with traditional straight wire arch fixation technique, and the study group was treated with Twin-block appliance. The correction effect, improvement of upper and lower jaw position and side orthodontic effect were compared between the two groups. Results The total effective rate of treatment in the study group was 92.00%, which was higher than 68.00% in the control group (P <0.05). There was no significant difference in SNA between the two groups after correction (P >0.05). After correction, SNB and ANB in the two groups were better than those before correction, and those in the study group were better than those in the control group (P <0.05). After correction, Goco, Co-Pg, Elime and LL-Elime in the two groups were better than those before correction, and those in the study group were better than those in the control group (P <0.05). Conclusion For patients angle class Ⅱ malocclusion, Twin-block appliance treatment can effectively induce mandibular function forward, improve the relationship between upper and lower jaw, effectively improve the patient's profile, and the clinical treat ment effect is better.