Methylcyclohexane (MCH) is considered as one of the most promising liquid organic hydrogen carriers (LOHCs) in terms of hydrogen storage and delivery. However, the dehydrogenation process of MCH is relatively difficult, which requires catalyst having high activity and stability. In this work, a catalyst of Pt/Al2O3 by doping Ga2O3 was prepared and tested in the dehydrogenation of MCH, resulting in both high activity and stability. After 176 hours of the reaction, the conversion of MCH is no significant decrease, and the toluene (TOL) selectivity was greater than 99%. The characterization results of the catalyst evidenced that the excellent performance of the catalyst is due to the introduction of Ga2O3, which prevents the growth of Pt species and results more positively charged Pt species. These Pt species can weaken the strength of the adsorption between Pt and dehydrogenation products, making dehydrogenation products more easily to be desorbed, which achieving high activity and stability. The catalyst shows great potential for industrial application in the future. This work provides theoretical guidance for designing highly stable dehydrogenation catalysts.