A light source module includes a light source, a dichroic unit, a color wheel and a wavelength conversion unit. The light source is configured to emit a light. The dichroic unit is opposite to the light source and configured to reflect a portion of the light as a first illumination light in a first direction and reflect a portion of the light as a second illumination light in a second direction inverse to the first direction. The color wheel is opposite to the dichroic unit and configured to at least receive the first illumination light. The color wheel has a blue filter area, a green filter area and a red filter area. The wavelength conversion unit is opposite to the color wheel and the dichroic unit and configured to at least receive the second illumination light and provide a converted light to the color wheel.