Abstract: In this paper, CeO_x was doped into the catalytic system and cerium-doped carbon nanomaterial was prepared by roasting at high temperature in N₂ atmosphere as the carrier. Rh/CeO_x-C₃N₄ catalyst was synthesized by loading the active component Rh onto CeO_x-C₃N₄ carrier through impregnation reduction method, and its influence on catalytic performance of hydrazine hydrate dehydrogenation was investigated. The results showed that there was a synergistic effect between the active component Rh and CeO_x in Rh/CeO_x-C₃N₄ catalyst, and the doping of CeO_x effectively dispersed and stabilized the metal active component, providing more active sites for catalytic reaction. Therefore, the catalyst has good catalytic activity for the dehydrogenation of hydrazine hydrate. The prepared Rh/CeO_x-C₃N₄ catalyst showed the best catalytic activity for hydrazine hydrate, and the initial conversion TOF was up to 1959.24 h⁻¹. After 5 cycles, the catalytic activity remained good, indicating good durability.