Objective To explore the effect of adjuvant therapy with minocycline hydrochloride ointment on gingival aesthetics and oral health in fixed orthodontic patients. Methods A total of 80 patients with fixed orthodontics admitted to Guilin Hospital of Integrated Traditional Chinese and Western Medicine from January 2023 to January 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 40 patients in each group. The control group received initial periodontal therapy, and the observation group received adjuvant minocycline hydrochloride ointment on the basis of initial periodontal therapy. The gingival aesthetics [modified Pink Esthetic Score (mPES)], periodontal health indicators [plaque index (PLI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD)], oral health-related quality of life [Oral Health Impact Profile-14 (OHIP-14)] and adverse reaction rate were compared between the two groups. Results After 4 weeks of treatment, the mPES of the observation group was higher than that of the control group, while the PLI, GI, SBI, PD and OHIP-14 score were lower than those of the control group (P<0.05). There was no statistically significant difference in the incidence of adverse reactions between the two groups (P>0.05). Conclusion Adjuvant therapy with minocycline hydrochloride ointment can improve gingival morphology and aesthetics, alleviate gingival inflammation, and maintain periodontal and oral health, with favorable safety. It is worthy of clinical application.