<p>In order to solve the problems of low hydrogen absorption rate and poor hydrogen storage efficiency caused by the thermal-mass coupling effect in the process of metal hydride hydrogen storage, this paper takes LaNi₅ metal hydride hydrogen storage tank as the research object, establishes its heat-mass-flow multi-physics field coupling model, and compares the hydrogen storage performance of finless, built-in finned heat exchange tubes and inner wall rectangular finned hydrogen storage tanks. The results show that inserting fins on the inner wall can significantly improve the heat transfer efficiency, reduce the temperature gradient and shorten the hydrogen absorption time. Comparing the hydrogen absorption performance of different fin structures, it was found that the wavy fin design exhibits the best absorption performance among the configurations studied under identical boundary conditions. On this basis, the structural parameters of the wavy fins are optimized and designed, and the optimal fin peak spacing and amplitude ratio is determined to be 1.5:1. This study can provide a theoretical basis and engineering reference for the design of solid-state hydrogen storage systems.</p>