A light source device (100, 200, 300), comprising an excitation light source, a supplementary light source, a color wheel (108, 208, 308), a polarization light splitter, and a light deflector, wherein: the excitation light source is configured to emit a first color light to the color wheel (108, 208, 308); the color wheel (108, 208, 308) comprises a first light-processing region, a wavelength conversion region, and a supplementary light-processing region, the first light-processing region and the wavelength conversion region are sequentially arranged along a circumferential direction, the first light-processing region is configured to receive the first color light in a first time period and configured to transmit or reflect the first color light, and the wavelength conversion region is configured to receive the first color light in a second time period and emit an excited light; and the supplementary light-processing region is located on an inner side or an outer side of the wavelength conversion region, and the supplementary light source is configured to emit, during the second time period, a supplementary light that broadens a color gamut and at least partially overlaps with a spectrum of the excited light, and the supplementary light exiting from the supplementary light-processing region is combined with the excited light exiting from the wavelength conversion region, characterized in that, the excitation light source comprises a first light source configured to emit the first color light having a first polarization state and a second light source configured to emit the first color light having a second polarization state, the polarization light splitter comprises a first region and a second region, the second region is configured to receive the first color light having the first polarization state emitted by the first light source, the light deflector is arranged between the second light source and the polarization light splitter and is configured to control the first color light having the second polarization state emitted by the second light source to be incident in the first region in the first time period and incident in the second region in the second time period. the excitation light source is configured to emit a first color light to the color wheel (108, 208, 308); the color wheel (108, 208, 308) comprises a first light-processing region, a wavelength conversion region, and a supplementary light-processing region, the first light-processing region and the wavelength conversion region are sequentially arranged along a circumferential direction, the first light-processing region is configured to receive the first color light in a first time period and configured to transmit or reflect the first color light, and the wavelength conversion region is configured to receive the first color light in a second time period and emit an excited light; and the supplementary light-processing region is located on an inner side or an outer side of the wavelength conversion region, and the supplementary light source is configured to emit, during the second time period, a supplementary light that broadens a color gamut and at least partially overlaps with a spectrum of the excited light, and the supplementary light exiting from the supplementary light-processing region is combined with the excited light exiting from the wavelength conversion region, characterized in that, the excitation light source comprises a first light source configured to emit the first color light having a first polarization state and a second light source configured to emit the first color light having a second polarization state, the polarization light splitter comprises a first region and a second region, the second region is configured to receive the first color light having the first polarization state emitted by the first light source, the light deflector is arranged between the second light source and the polarization light splitter and is configured to control the first color light having the second polarization state emitted by the second light source to be incident in the first region in the first time period and incident in the second region in the second time period.