A light source system, characterized by comprising: a first light source; a first wavelength conversion device capable of being excited by an excitation light emitted by the first light source to generate a first excited light; a second wavelength conversion device capable of being excited by the excitation light emitted by the first light source to generate a second excited light, wherein the first wavelength conversion device and the second wavelength conversion device both are monochromatic fluorescent wheels; a light path conversion element configured to make the excitation light emitted by the first light source irradiate the first wavelength conversion device and the second wavelength conversion device in turn; and a light combining unit configured to combine the first excited light with the second excited light; wherein the light path conversion element is a rotating wheel that rotates around its own axis, and the rotating wheel has a first working position and a second working position; the rotating wheel comprises a first transmission area and a first reflection area arranged in a circumferential direction, the rotating wheel further comprises a second transmission area, and the first reflection area and the second transmission area are arranged along a radial direction of the rotating wheel; the light source system further comprises a reflection element; the first light source obliquely irradiates the rotating wheel; under a condition that the rotating wheel is at the first working position, the excitation light emitted by the first light source irradiates the first wavelength conversion device after passing through the first transmission area; under a condition that the rotating wheel is at the second working position, the excitation light emitted by the first light source irradiates the second wavelength conversion device after being reflected by the first reflection area, reflected by the reflection element, and passing through the second transmission area sequentially. a first light source; a first wavelength conversion device capable of being excited by an excitation light emitted by the first light source to generate a first excited light; a second wavelength conversion device capable of being excited by the excitation light emitted by the first light source to generate a second excited light, wherein the first wavelength conversion device and the second wavelength conversion device both are monochromatic fluorescent wheels; a light path conversion element configured to make the excitation light emitted by the first light source irradiate the first wavelength conversion device and the second wavelength conversion device in turn; and a light combining unit configured to combine the first excited light with the second excited light; wherein the light path conversion element is a rotating wheel that rotates around its own axis, and the rotating wheel has a first working position and a second working position; the rotating wheel comprises a first transmission area and a first reflection area arranged in a circumferential direction, the rotating wheel further comprises a second transmission area, and the first reflection area and the second transmission area are arranged along a radial direction of the rotating wheel; the light source system further comprises a reflection element; the first light source obliquely irradiates the rotating wheel; under a condition that the rotating wheel is at the first working position, the excitation light emitted by the first light source irradiates the first wavelength conversion device after passing through the first transmission area; under a condition that the rotating wheel is at the second working position, the excitation light emitted by the first light source irradiates the second wavelength conversion device after being reflected by the first reflection area, reflected by the reflection element, and passing through the second transmission area sequentially.