A light-filtering module includes a light-source module, a dichroic mirror and a first image unit. The light-source module outputs a light beam. The dichroic mirror divides the light beam into a first colored light and a dual colored light. The first image unit provides the first colored light with image information. The light-filtering module includes a light-filtering unit and a driving unit. The light-filtering unit is located between the dichroic mirror and the first image unit is located at a light path of the first colored light. The driving unit includes a coupling element coupled to the light-filtering unit and a driving element utilized to drive the coupling element. The driving element drives the light-filtering unit, switching between a first status and a second status by the coupling element. A wide-wavelength spectrum and a narrow-wavelength spectrum are provided when the light-filtering unit is in the first and second statuses, respectively.