The invention provides a light source. The light source comprises an excitation light source and a reflective bowl, the excitation light source is used for emitting exciting lights, the inner surface of the reflective bowl serves as a first reflecting surface, the first reflecting surface includes a light outlet and at least one focal point, the light source further comprises a wavelength conversion element and a reflecting device, the wavelength conversion element is located on the focal point of the first reflecting surface, the wavelength conversion element is used for absorbing the exciting lights and emitting stimulated lights, the reflecting device is located on the wavelength conversion element and faces to one side of the light outlet of the reflective bowl, and the reflecting device is used for reflecting the stimulated lights. The excitation light source is located on the outside of the reflective bowl. According to the light source, the light emitting solid angle of the stimulated lights emitted by the wavelength conversion layer can be remarkably reduced by the aid of the reflecting device, the length of the reflective bowl is greatly reduced, simultaneously the excitation light source is placed on the outside of the reflective bowl, and thereby all of stimulated lights emitted by the wavelength conversion layer can be efficiently reflected into the reflective bowl.