A projection apparatus, an illumination module and a color-level correcting method therefor are provided. The projection apparatus comprises a projection lens, an imaging unit and an illumination module. The illumination module comprises a light source, a color wheel and a controlling unit. The light source provides a light beam. The color wheel is disposed on an optical path of the light beam and the controlling unit is connected to the color wheel and the imaging unit. A plurality of color wheel indices is stored in the controlling unit. When the projection apparatus receives an image signal, the controlling unit selects one of the color wheel indices according to the received image signal and controls the imaging unit according to the selected color wheel index. The projection apparatus automatically selects the corresponding color wheel index according to the received image signal for projecting an image with good tints and color-level performance.