Visualizing hydrogenation processes in metals in real-time is important to various hydrogen-involved applications. However, observing hydrogen diffusion was limited by transmission electron microscopy, and the kinetics of hydrogenation in the interior of the metals was not reported. Here we proposed an optical microscopy-based visualization of palladium hydrogenation from diffusion surface to the interior by introducing a fast-response mechanical platform that transforms the hydrogen diffusion into self-organized ordered wrinkles with sharp optical contrast. This platform is an Au/Pd double layer on elastomer which results in directional hydrogenation from sidewall to the interior. The kinetics of hydrogenation in the interior of the palladium along the diffusion direction was monitored in real-time. This platform will enable in-situ visualization of atom/ion diffusion on metals that are crucial in energy storage and hydrogen detection.