Objective: To investigate the clinical efficacy of tooth-supported Hyrax expander combined with protraction facemask in the treatment of early Class III malocclusion during the mixed dentition period, and to provide clinical evidence for the efficient treatment of this condition.Methods: A total of 10 patients aged 6–13 years with skeletal Class III malocclusion during the mixed dentition period, who were treated at the People"s Hospital of Shache County from January 2025 to December 2026, were selected as the research subjects and randomly divided into the study group (n = 5) and the control group (n = 5) using a random number table. The study group was treated with tooth-supported Hyrax expander combined with protraction facemask, while the control group was treated with FR-III functional appliance. Before and after treatment, all patients underwent comprehensive oral examinations, panoramic radiography, CBCT, and intraoral scanning. The SNA angle, SNB angle, ANB angle, overjet, upper lip protrusion (ULP), and lower lip protrusion (LLP) were measured. Data were analyzed using SPSS 24.0 software. Quantitative data were expressed as mean ± standard deviation, and intergroup comparisons were performed using t-tests. A P value of less than 0.05 was considered statistically significant.Results: After treatment, the ANB angle in the study group improved from (-1.6° ± 0.4°) to (0.9° ± 0.3°), the overjet improved from (-3.3 mm ± 0.6 mm) to (2.2 mm ± 0.4 mm), and ULP and LLP improved to (1.8 mm ± 0.5 mm) and (1.5 mm ± 0.4 mm), respectively. The improvements in all these parameters were significantly greater than those in the control group (all P < 0.05). The average treatment duration in the study group was (8.6 ± 1.3) months, which was shorter than that in the control group (12.5 ± 1.6 months, P < 0.05). The VAS pain score in the study group was (2.0 ± 0.7) points, which was lower than that in the control group (3.9 ± 0.9 points, P < 0.05).Conclusion: The combination of tooth-supported Hyrax expander and protraction facemask for the treatment of early Class III malocclusion can significantly improve the skeletal relationship and occlusal status of patients, shorten the treatment duration, and reduce treatment discomfort. The clinical efficacy is definite and suitable for promotion and application in children during the mixed dentition period.