The catalytic performance strongly relies on the composition, structure, and property of the material used. Earth-abundant tungsten oxides family (WO_x≤3) has received considerable attention in photocatalysis, electrochemistry and catalytic hydrogenation due to its highly tunable structure and unique physicochemical properties. Substantial efforts have been made by us to improve the photocatalytic activity of WO_x≤3 by enhancing light harvesting, charge transfer and separation, including defect engineering, morphology control, and hetero-junction construction. Additionally, the semiconductor-to-metal transition of WO_x≤3 has been found with the increase of defect concentration, suggesting H₂ can be activated on them in a similar way of a metal catalyst. As a result, WO_2.72 also can function as a versatile and efficient catalyst for the saturation of olefins and selective transform of nitroarenes to anilines.