Abstract: Ammonia borane (AB) has a hydrogen mass fraction of 19.6% and is widely regarded as a safe and efficient medium for hydrogen storage and release. However, developing an effective catalyst to drive hydrogen evolution via AB hydrolysis remains a significant challenge. Carbon nitride (CN) materials exhibit a distinctive band structure, outstanding chemical stability, and a coordination framework composed of nitrogen and carbon atoms. The lone electron pairs on nitrogen atoms enhance their coordination with metal atoms more readily than those on carbon atoms. Consequently, most metal atoms preferentially coordinate with nitrogen, making CN a valuable support material for stabilizing noble-metal catalysts. Research indicates that noble metal catalysts, including ruthenium (Ru), silver, palladium, platinum, and rhodium, exhibit exceptionally high catalytic activity in hydrogen production via AB hydrolysis. Among these, Ru-based catalysts demonstrate superior performance in AB hydrolysis and are relatively more cost-effective than other noble metal-based catalysts. However, Ru nanoparticles are prone to agglomeration, highlighting the need for suitable support materials to mitigate this issue and enhance their stability. In this study, CN was synthesized via high-temperature calcination using melamine, cyanuric acid, and citric acid as raw materials. Subsequently, a Ru/CN-supported nanocatalyst was prepared via an impregnation-reduction method. Various characterization techniques were used to analyze the structural composition and microstructure of the catalysts. Additionally, the effects of different factors on the hydrogen production rate during the hydrolysis of ammonia borane (NH₃BH₃, AB) were systematically investigated. The results revealed that the Ru/CN catalyst exhibits an irregular morphology with a rough surface and depressions, which enhance its surface area and facilitate the formation of active metal sites. The lattice stripe spacing of 0.211 nm corresponds to the (002) crystal plane of Ru, confirming the successful loading of Ru nanoparticles onto the CN support. Furthermore, the Ru nanoparticles were highly dispersed on the support surface, providing abundant active sites for the hydrolytic dehydrogenation reaction of AB. The X-ray photoelectron spectroscopy full spectrum of the Ru/CN catalyst displayed distinct characteristic peaks for carbon (C), nitrogen (N), oxygen (O), and Ru, further verifying the successful incorporation of Ru onto the CN support. The detection of elemental Ru confirmed the successful reduction of Ru³⁺ by sodium borohydride. The presence of Ru in a higher oxidation state is likely due to the partial oxidation of elemental Ru during characterization or performance testing. The Ru/CN catalyst, with a Ru loading of 0.05 mmol, achieved a TOF value of 446.4 min^–1. The AB hydrolysis hydrogen production reaction catalyzed by Ru/CN can be approximated as a first-order reaction with respect to the catalyst amount. Increasing the reaction temperature enhances the effective collision frequency between reactant molecules, thereby facilitating hydrogen production. Calculations and analyses revealed that the concentration of AB positively influences the Ru/CN-catalyzed reaction, with an activation energy of 53.6 kJ·mol^–1. After five cycles of use, the Ru/CN catalyst remains effective in catalyzing the complete hydrolysis of AB for hydrogen production. This study offers a promising pathway for designing efficient noble-metal catalysts for AB hydrolysis.