A system for testing a spectral response speed of a tunable filter is disclosed, which includes a collimating light source, a beam splitting element, a focusing lens, and an image recording device of light spot position arranged successively. The tunable filter is disposed between the collimating light source and the beam splitting element and configured to be continuously tuned within a certain wavelength range during testing. The beam splitting element is used to form light beams of different wavelength bands passing through the tunable filter into diffracted beams or refracted beams corresponding to different wavelength bands. The focusing lens is used to perform focusing. The image recording device of light spot position is used to record change information about positions where the diffracted beams or refracted beams corresponding to different wavelength bands are imaged.