TiO2-supported Au nanocatalysts are highly attractive for the water gas shift (WGS) reaction due to their high catalytic activity at low temperatures. Herein, the (Au/TiO2–x)OP catalyst synthesized by the combination of warm and cold plasmas exhibits a high WGS reaction rate of 1.63 mol·gAu–1·h–1 at 120 °C, being one of the highest WGS rates among Au/TiO2 catalysts. The warm plasma generates a large amount of oxygen vacancies, while the cold plasma treatment generates small Au nanoparticles and interfacial sites. The (Au/TiO2–x)OP catalyst features two kinds of abundant active sites including Auδ+-Oδ−-Ti4+ and Au0-Ov-Ti3+, which accelerate the WGS reaction simultaneously along the intermediate and redox reaction pathways, respectively.