Engineering of advanced semiconductor photocatalysts for CO2 conversion to solar fuels is a promising strategy to solve the greenhouse effect and energy crisis. Herein, hierarchical urchin-like yolk@shell TiO2–xHx decorated with core/shell Au–Pd plasmonic nanoparticles (HUY@S-TOH/AuPd) have been prepared using a multistep process and are employed as an advanced visible light active photocatalyst in CO2 conversion to CH4 with a rate of 47 μmol/gcat·h (up to 126 μmol/gcat after 7 h). Different engineered sites in this structure for high gas adsorption, powerful visible light activation, and intense electron transportation are responsible for the observed high photocatalytic CO2 conversion efficiency. The present smart design process can produce considerable cooperation in not only disclosing the architectural engineering for the improvement of photoconversion efficiency but also disclosing it as a viable and appropriate photocatalytic process to sustainable energy production.