Using ammonium molybdate and chloroplatinic acid as raw materials, through the in-situ temperature-programmed carbonization process, Pt/MoC catalysts with different loading amounts were synthesized and their catalytic performances in the hydrogen evolution reaction (HER) of electrolyzed water were investigated. The microstructure and physicochemical properties of the catalysts were characterized by XRD, BET, SEM, TEM and XPS. The results show that the Pt loading changes the topological structure of molybdenum carbide during the carbonization process, and the Pt-loaded sample more easily forms the α-Mo2C phase. The loading of Pt has a significant effect on the molybdenum carbide catalyst in the HER reaction. The 1.6 Pt/MoC catalyst exhibits an optimal catalytic effect (overpotential ηonset = 108 mV, Tafel slope b = 74 mV∙dec-1) and The lower impedance (18.77 Ω) is comparable to commercial Pt/C catalysts.