A wind turbine blade device includes a rotating unit including a blade module concentrically connected to a rotating shaft thereof and having a plurality of radially curved channels each having inlet and outlet ends. The inlet and outlet ends of the radially curved channels are configured to respectively permit flow of the flow body into and out thereof. An outer tube includes a tube body surrounding the rotating unit, and a plurality of rib plates provided in the tube body. The outlet end of each radially curved channel corresponds to one of the rib plates, and each radially curved channel forms an included angle with a corresponding rib plate such that the flow body flowing out of the outlet end can impact upon the corresponding rib plate.