A light emitting device includes a first light source, a light guiding system and a wavelength conversion device. The first light source is configured to emit first excitation light which enters the light guiding system via an incident light channel. The light guiding system is configured to guide the first excitation light to the wavelength conversion device. The wavelength conversion device includes a reflecting segment that reflects the first excitation light to form second excitation light. The light guiding system is further configured to collect the second excitation light and guide the second excitation light to exit via an output light channel. The first excitation light and the second excitation light have non-overlapping light paths.