Objective The study was designed to investigate the clinical efficacy of clonidine transdermal patch combined with vitamin D3 drops in the treatment of tic disorder in children and to analyze the relationship between the serum 25 hydroxy vitamin D level and its clinical efficacy. Methods A total of one hundred and fifteen children with tic disorders who attended our pediatric neurology outpatient department from January 2020 to June 2022 were randomly divided into three groups：45 cases in the clonidine transdermal patch+vitamin D3 drops group，45 cases in the clonidine transdermal patch group，and 30 cases in the vitamin D3 drops group. Comparison of Yale General Tic Severity Scale（YGTSS）score and serum 1⁃25 hydroxy vitamin D levels between the three groups of 0，4 and 12 weeks after treatment were made to determine efficacy and safety. Results Compared with pre ⁃treatment，YGTSS scores were lower in all three groups at 4 and 12 weeks of treatment compared with pre ⁃ treatment（P < 0.05）. At 4 weeks after treatment，YGTSS scores were reduced in the clonidine transdermal patch + vitamin D3 drops group and clonidine transdermal patch compared with the vitamin D3 drops group（P < 0.05）. At 12 weeks after treatment，YGTSS scores were lower in the clonidine transdermal patch + vitamin D3 drops group compared with the other two groups（P < 0.05）. Serum 25 hydroxyvitamin D levels were higher in all three groups after 12 weeks of treatment compared with those before treatment（P < 0.05）. Conclusion Clonidine trans⁃ dermal patch + vitamin D3 dr ops group was more effective than other 2 groups in treating tic disorder in chil⁃ dren，and vitamine D may be helpful in the treatment of Tic disorder.