The invention relates to a large-pore-size mesoporous carbon/silicon dioxide loaded gold nano-catalyst and a synthesis method thereof. The catalyst has a face-centered cubic ordered structure, the specific surface area is 200m<2>/g to 700<2>/g, the pore volume is 0.30cm<3>/g to 0.60cm<3>/g, the pore size is 7.0nm to 20nm, and the mass percent of Au is 0.5% to 2.5%. During preparation, the mesoporous carbon/silicon dioxide loaded gold nano-catalyst is synthesized in one step through mixing a macromolecular surfactant, which serves as a template agent, with a gold source, a carbon source and a silicon source and carrying out solvent-induced volatilization self-assembly. Compared with the prior art, the catalyst provided by the invention has the characteristics of high-ordered mesoscopic structure, adjustable pore size (7.0nm to 20nm), relatively small gold nano particle size (3nm to 5nm), adjustable gold content (0.5wt% to 2.5wt%), and the synthesis method is simple, is low in cost and facilitates the implementation of large-scale production, thereby having very good economic application prospect.