Nowadays, metal hydrides are generally deemed as one of the most potential materials that are in favor of compact hydrogen storage for industrial applications. This work was committed to evaluate the thermal performance of a circular-shaped-tube thin double-layered hydrogen storage reactor using a three-dimensional model. Finite element simulations were conducted to systematically study the influences of structural geometries, cooling patterns, and material thermophysical properties on the heat diffusion behavior under the framework of convection heat transfer. The results indicate that the proposed model effectively characterizes temperature evolutions during hydrogen absorption process. Moreover, a statistical analysis was performed to reveal the sensitivity sequence of these factors on the total thermal performance, suggesting that decreasing the hydride layer thickness, increasing the number of U-shaped cooling tubes, accelerating the cooling fluid flow rate, and enhancing the thermal conductivity are more beneficial to the thermal performance improvement. Detailed analysis confirms the possibility of developing the present hydrogen storage tank utilizing metal hydrides for engineering practice.