The invention provides controllable synthesis of a carbon nitride-bismuth tungstate compound nano-material. The method comprises the following steps: firstly, combining carbon nitride into a bismuth tungstate material by adopting a one-step hydrothermal synthesis method; and then, further combining bismuth tungstate with the carbon nitride-bismuth tungstate compound material by a high-energy ball milling method. The compound nano-material has a sheet structure and is formed by interlacing ultrathin nano-plates having thickness of 18-24nm, the specific surface area of the material is 240-280m<2>/g, the pore volume is 0.24-0.30cm<3>/g, and the performance is very excellent. Furthermore, the compound nano-material has the advantages of simple process, low cost, short cycle, environment friendliness and the like, is applicable to industrial large-scale production, and has excellent photocatalytic activity when being applied to photocatalytic reactions.