<p>This study systematically explores the effects of hydrogen-rich gas injection on the high-temperature metallurgical properties of sinter, with particular emphasis on the regulatory roles of raw material ratios, basicity, and pellet addition proportions in controlling softening–melting–dripping behavior, permeability, and slag formation. By employing high-temperature melting–dripping tests, it is revealed that the sintered ore produced by hydrogen-rich gas injection with higher Al₂O₃ content and basicity contains more SFCA phases, significantly enhancing the softening–melting performance of sintered ore while simultaneously expanding the temperature range, leading to deteriorated gas permeability in the burden layer. The addition of pellets effectively improves overall burden permeability, with optimal performance observed at a 45% pellet proportion. Meanwhile, the sintered ore produced by hydrogen-rich gas injection exhibits the lowest pressure difference and superior permeability compared to conventional sintered ore. The research can provide theoretical and technical support for optimizing hydrogen-rich sintering processes and low-carbon blast furnace ironmaking.</p> Graphical Abstract <p></p>