Catalysis is essential for chemical industry and contributes to 90 percent of current chemical processes. For cleaner and more efficient chemical processes, the focus of catalysis engineering should combine macro-level process design and meso-level reactor design with a micro-level design of active sites, nanostructure reaction pathways, and kinetics, for which in situ solid-state NMR spectroscopic techniques are required.[1] We recently developed a micro-reactor inside a MAS probe for an in situ solid-state NMR spectroscopy.[2] Based on an understanding of catalytically active species and their functions as solid catalysts by in situ NMR techniques, it is possible to design and control the catalytic properties of catalysts at the nanoscale level for desired reactions.[3] This more strategic approach will promote catalyst development and provide an alternative to the classical trial-and-error approach, with prospects for viable pre-design.[4] In addition, in-situ NMR spectroscopic techniques can provide specific information about working catalysts, reaction pathways, and kinetics, offering the essential parameters for reactor and process design and modulation.[5] Based on the powerful in situ NMR techniques, a series of green and highly efficient catalytic processes were developed for alkylation, isomerisation, disproportionation, and Beckmann rearrangement in the petrochemical industry, for the deoxygenation of bio-oil in the bio-refining, and for the chemoselective oxidation and hydrogenation for the production of fine chemicals.