A wavelength conversion device and a light-emitting device and a projection device using the wavelength conversion device are provided. The wavelength conversion device includes a substrate capable of rotating around a rotating shaft, the substrate includes a first surface and a second surface opposite to each other, and an annular side surface, which is formed between the first surface and the second surface and is not perpendicular to the first surface. The first surface is provided with a wavelength conversion material layer, and the annular side surface includes a first area and a second area. The first area and the second area are used to reflect incident light beams.