We put forward a strategy for one-step preparation of SiO₂-based monolithic TS-1 catalysts with optimal hierarchical scaffolds by combining the flow field simulation of the reactor and 3D printing technology. Structured monolithic catalysts have attracted increasing attention in the petrochemical industry due to their advantages of high heat and mass transfer rate, easy scale-up, and reusability. Tunable hierarchical porosity from nano to micro scales, suitable pore characteristics, and numerous active sites have been obtained by innovatively combining the spherical porous structure of TS-1/SiO₂ material, direct ink writing (DIW) and post-sintering processes. Combined with computational fluid dynamics (CFD) analysis, the effects of different channel offset angles, axial and radial channel sizes on the 3D printed monolithic TS-1 in the catalytic reaction of one-step oxidation of ethylene to ethylene glycol (EG) were verified. 3D-printed monolithic TS-1 catalysts exhibited superior crush strengths (135.11 N/cm) and extraordinary catalytic efficiency, in which the yield of EG reached 82.7%, and the utilization of hydrogen peroxide reached 85.3%. Moreover, the 3D printed TS-1 monolith maintained high catalytic performance over 5 reusable cycles, which solved the problem that traditional catalysts are difficult to be manufactured, separated, and recycled, and presented considerable prospects in reactions requiring fluid agitation. This strategy can be extended to other 3D printing catalytic systems requiring separation and recycling to achieve further process intensification and catalytic efficiency improvement.