A high-sensitivity double-roughness-structure (DRS) and its innovative manufacturing processes are originally proposed for the improvement on the sensing of the non-reactive molecule. The nitrogen molecules are served as the non-reactive test target in the study. In the DRS, the high roughness graphene is embedded into/onto the roughness surface of the porous silicon, and such the porous silicon is specially made by the “bottom-hole assisted approach” to get high-quality films. It is proved that the DRS reveals the double reinforcement on the improvement of the sensitivity based on the high surface-to-volume ratio in the sensing on non-reactive molecules.