A wind power generation control device, coupled between a wind power generator and a power grid, includes a converter unit and a switching unit. The converter unit includes a generator-side converter, a DC bus capacitor and a grid-side converter, wherein an AC-side of the generator-side converter is coupled to a rotor-side of the wind power generator, a DC-side of the generator-side converter is coupled to the DC bus capacitor, a DC-side of the grid-side converter is coupled to the DC bus capacitor, and an AC-side of the grid-side converter is coupled to the power grid. The switching unit is configured to switch the wind power generation control device between the doubly-fed power generation operating mode and the full-power operating mode according to a wind speed. A wind power generation system uses the wind power generation control device.