Uniformly dispersed Ag nanowires were obtained in SBA-15 at a short deposition time of 5 minutes in supercritical CO2. The short deposition time relied not only on the near-zero surface tension of supercritical CO2 but also on the addition of ethylene glycol as co-solvent. It was found that a small amount of the precursors were reduced into Ag0 by ethylene glycol and acted as nuclei leading to a non-equilibrium sorption, which representing a rapid adsorption of precursor onto the substrate. In order to provide an overall understanding of the exact role played by ethylene glycol when preparing Ag@SBA-15 in supercritical CO2, the dissolution enhancement of precursor by the co-solvent, the diffusion properties of the precursor into the nano-scale channels and the interaction between the precursor and the substrates were all taken into consideration. Finally, this method was successfully extended to other porous substrates such as γ-Al2O3, SiO2 and KIT-6 offering its great opportunities of applications in industry.