Objective To compare the clinical effect of Duraphat and GC tooth friendly paste in inhibiting enamel demineralization during fixed orthodontic treatment. Methods A total of 120 patients (2526 teeth) received orthodontic treatment in our hospital were selected in the study, which were divided into group A (40 cases, 850 teeth), group B (40 cases, 896 teeth) and group C (40 cases, 780 teeth) by random number table method. During treatment, patients of group A used GC tooth friendly paste to coat outer surface of teeth once per month, patients of group B used Duraphat to coat and group C was blank control group without special treatment. 6 months after correction, the status of enamel demineralization was compared among groups. Results There was grade 3 enamel demineralization in all groups before correction, the number of areas with enamel demineralization showed no significant difference among groups (P>0.05). In the sixth month after the beginning of correction, there were significant differences in the number of areas with enamel demineralization among groups (P<0.001). There was no significant difference in enamel demineralization index among groups before correction (P>0.05). In the sixth month after the beginning of correction, the index was increased significantly, there was no significant difference between group A and group B, it was higher in group C than group A and group B (P<0.05). Conclusion Both of Duraphat and GC tooth friendly paste can effectively inhibit enamel demineralization in fixed orthodontic treatment. The appropriate scheme can be chosen according to the actual condition.