The auto-test equipment for relative spectral response of charge coupled devices (CCD) was designed and realized. The equipment covered the range of 400 to 950 nm. Firstly, testing theory of relative spectral response for detectors was introduced. Secondly, taking the high sensitive and broad spectral scientific spectrometer-QE65000 as reference, auto-test equipment for relative spectral response was built up by direct comparison method in the same radiation field. Uncertainty analysis showed that the maximum uncertainty of the equipment was less than 6.21%. This auto-test equipment can be used in the CCD assessment and its photoelectrical parameters testing.