Abstract: Utilizing phase change materials for thermal management in solid-state hydrogen storage devices can fully leverage the heat during the hydrogen storage and release processes and make the heat exchange system more lightweight and compact. However, previous phase change material layouts typically adopted a winding structure, which suffers from high radial thermal resistance, making it difficult to apply to large-capacity solid-state hydrogen storage devices. Based on this, for a kilogram-level solid-state hydrogen storage device, this paper proposes a tube-and-shell material filling structure coupled with phase change heat transfer and constructs a multi-physics model of its coupled hydrogen-thermal transport. The effects of the spatial layout of hydrogen storage materials, operating parameters, and physical property parameters on hydrogen storage performance were systematically studied. The results indicate that arranging the metal hydride （MH） in the tube side can significantly increase the effective heat exchange area and achieve uniform filling of the metal hydride, resulting in superior hydrogen absorption/desorption rates compared to the design with MH in the shell side. Lowering the working pressure or increasing the phase transition temperature of the phase change material can accelerate the hydrogen desorption reaction rate. Conversely, increasing the working pressure is an effective means to accelerate the hydrogen absorption reaction. Enhancing the thermal conductivity of the metal hydride bed, as well as the thermal conductivity of the phase change material in its solid state （during desorption） and liquid state （during absorption）, can strengthen heat transfer and help improve the reactor's absorption/desorption performance. The tube-and-shell solid-state hydrogen storage device structure with coupled phase change thermal management proposed in this study can provide theoretical guidance for the development of efficient, compact, and large-capacity solid-state hydrogen storage reactors and promote their engineering applications.