An illumination module includes a light source, a color wheel, an actuator, and a reflective unit. The light source is for providing a light beam with a first wavelength band. The color wheel has an outer annular section and an inner annular section. The color wheel includes a wavelength conversion segment disposed at the outer annular section and a plurality of filter segments disposed at the inner annular section. The wavelength conversion segment is configured to convert a portion of the light beam with the first wavelength band into a light beam with a second wavelength band, and has at least one wavelength conversion material including yttrium aluminum garnet (YAG) phosphors. The filter segments are respectively configured to filter desired wavelength bands of the light beam. The reflective unit is configured to reflect the light beam passing through the outer annular section to the inner annular section.