The invention relates to a flower-like structured CuS material as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a cupric compound and a solvent, and sufficiently stirring the components at certain temperature so as to obtain a homogeneous solution; under acute stirring, slowly adding a sulfur-containing compound into the homogeneous solution, and performing temperature-keeping treatment; transferring the solution into a hydrothermal reaction kettle, and performing a sealed heating reaction at certain temperature, performing cooling till the room temperature, performing filtration and collection, washing the product, performing filtration again, performing vacuum drying, and grinding the product, thereby obtaining a black product, that is, the flower-like structured CuS material. The flower-like structured CuS material can be applied to photocatalytic degradation dye wastewater. Compared with the prior art, the flower-like structured CuS material is wide in visible light response range of CuS, and high in visible light utilization rate.