Objective To explore the nursing effect of oral irrigator in patients wearing fixed appliance. Methods A total of 130 patients who received orthodontic treatment with fixed appliances in our hospital from April to September 2023 were randomly divided into control group and observation group, with 65 patients in each group. The control group was given traditional oral nursing, and the observation group was given oral irrigator nursing. The quality of nursing, plaque index, gingival index, complications, and nursing satisfaction were compared between the two groups. Results The scores of nurse-patient communication, health education and nursing skills in the observation group were higher than those in the control group (P <0.05). The plaque index of the two groups after nursing was lower than that before nursing, and that of the observation group was lower than that of the control group (P <0.05). The gingival index of the two groups after nursing was lower than that before nursing, and that of the observation group was lower than that of the control group (P <0.05). The incidence of complications in the observation group was 3.08%, which was lower than 16.92% in the control group (P <0.05). The nursing satisfaction of the observation group was 96.92%, which was higher than 83.08% of the control group (P <0.05). Conclusion Oral hygiene nursing with oral irrigator for patients wearing fixed appliance can strengthen the quality of nursing, improve the nursing effect, reduce the plaque index and gingival index, and prevent complications.