A light source system, comprising: an excitation light source (301; 401; 501; 601; 701; 801; 901) for generating an excitation light; a wavelength conversion device (306; 406; 506; 606; 706; 806; 906) for converting the excitation light to a converted light; a first supplemental light source for generating a first supplemental light; a first light guiding device for directing the first supplemental light to the wavelength conversion device (306; 406; 506; 606; 706; 806; 906) which scatters and at least partially reflects the first supplemental light; a first light collection device for collecting the first supplemental light scattered and reflected by the wavelength conversion device (306; 406; 506; 606; 706; 806; 906), wherein relative sizes of the first light guiding device and the light collection device are such that a luminous flux of the first supplemental light that is lost due to the first light guiding device is less than or equal to a quarter of the first supplemental light collected by the first light collection device; wherein the first light collection device includes a reflection surface (3051; 4051; 5051; 6051; 7051) for reflecting the first supplemental light scattered and reflected by the wavelength conversion device (306; 406; 506; 606; 706; 906), and the first light guiding device is an opening (3052; 4052; 5052; 6052; 7052; 9052) on the reflection surface, through which the first supplemental light transmits; or wherein the first light guiding device is a light reflection device, which reflects the first supplemental light to the wavelength conversion device, characterized in that an area of the opening (3052; 4052; 5052; 6062; 7072) being less than or equal to a quarter of an area of the reflection surface (3051; 4051; 5051; 6051; 7051); or a projection area of the light reflection device on the first light collection device is less than or equal to a quarter of the area of the first light collection device, the first light collection device being a lens or a light reflection surface; the light source system being further characterized in that spectral ranges of the first supplemental light and the converted light at least partially overlap, or a difference of dominant wavelengths of the converted light and the first supplemental light is less than 20 nanometers. an excitation light source (301; 401; 501; 601; 701; 801; 901) for generating an excitation light; a wavelength conversion device (306; 406; 506; 606; 706; 806; 906) for converting the excitation light to a converted light; a first supplemental light source for generating a first supplemental light; a first light guiding device for directing the first supplemental light to the wavelength conversion device (306; 406; 506; 606; 706; 806; 906) which scatters and at least partially reflects the first supplemental light; a first light collection device for collecting the first supplemental light scattered and reflected by the wavelength conversion device (306; 406; 506; 606; 706; 806; 906), wherein relative sizes of the first light guiding device and the light collection device are such that a luminous flux of the first supplemental light that is lost due to the first light guiding device is less than or equal to a quarter of the first supplemental light collected by the first light collection device; wherein the first light collection device includes a reflection surface (3051; 4051; 5051; 6051; 7051) for reflecting the first supplemental light scattered and reflected by the wavelength conversion device (306; 406; 506; 606; 706; 906), and the first light guiding device is an opening (3052; 4052; 5052; 6052; 7052; 9052) on the reflection surface, through which the first supplemental light transmits; or wherein the first light guiding device is a light reflection device, which reflects the first supplemental light to the wavelength conversion device, characterized in that an area of the opening (3052; 4052; 5052; 6062; 7072) being less than or equal to a quarter of an area of the reflection surface (3051; 4051; 5051; 6051; 7051); or a projection area of the light reflection device on the first light collection device is less than or equal to a quarter of the area of the first light collection device, the first light collection device being a lens or a light reflection surface; the light source system being further characterized in that spectral ranges of the first supplemental light and the converted light at least partially overlap, or a difference of dominant wavelengths of the converted light and the first supplemental light is less than 20 nanometers.