The invention belongs to the technical field lighting equipment, and relates to a device for outputting white light from a single frequency laser beam through optical elements. The device comprises a single frequency laser beam A, a focusing lens L1 and a lens L2 forming a lens set and a fluorescence medium Y, and the focal lengths of the focusing lens L1 and the lens L2 are f1 and f2 respectively. The single frequency laser beam A is located on one side of the focusing lens L1 and perpendicular to the focusing lens L1, the lens L2 is disposed on the other side of the focusing lens L1, and the fluorescence medium Y is arranged behind the lens L2. The single-wavelength laser is used and is transmitted through the fluorescence medium optical device to generate new wavelength spectrum, the new wavelength spectrum and the original wavelength light are mixed in a proper mixing proportion to emit white light, and the problem of nonuniform color distribution in different areas of a light field due to the fact that more than two kinds of wavelength lights are mixed into the white light is avoided effectively; cost is low, and designability of a system light path is higher.