A double-light cabinet for testing a biological sample labeled with fluorochrome includes a case, in which a light unit and a diffusion unit are received. The light unit has two spot light sources to emit spot lights with specified wavelengths according to the test, and the diffusion unit diffuses the spot lights into surface lights, to which that the biological sample is exposed. The present invention further includes an amber filter unit to filter the surface light to enhance the signal of biological samples. Using the lights with specified wavelengths, the present invention may serve both functions of excitation and illumination of the biological sample.