The invention provides a light tunable filtering device, which comprises a prism for splitting light and an optical selector which are sequentially arranged along a light path, wherein the position and the size of a light transmittance region of the light selector can be adjusted; the light selector selects light with required wavelength from a spectrum projected from the prism to the light selector. According to the light tunable filtering device, continuous large-range wavelength tunable filtering can be realized; the stability is high; the light tunable filtering device is easy to operate; the occupied time is short; white light with relatively large aperture can be subjected to tunable filtering; and the application range of tunable filtering can be greatly expanded.