A wavelength conversion device includes a wavelength conversion plate, a reflective layer, a driving component and a thermal conductive layer. The wavelength conversion plate includes a lateral edge, at least one surface and a conversion region. The reflective layer is disposed on the surface of the wavelength conversion plate. The driving component is disposed near the lateral edge of the wavelength conversion plate and configured to displace the wavelength conversion plate. The thermal conductive layer is disposed on the surface of the wavelength conversion plate and thermally connected to the conversion region for conducting heat generated by the conversion region during a wavelength conversion. By disposing the thermal conductive layer on the surface of the wavelength conversion plate, the thermal conductive layer is thermally directly connected to the conversion region, so that the heat generated at the conversion region during the wavelength conversion is efficiently dissipated.