By coupling Elliptical Bent Crystal Spectrometer (EBCS) with X-ray CCD, a set of system (EBCS-XCCD) for measuring X-ray spectra was briefly described. The calibration procedures for absolute line and line intensity measurement were studied and formulae of identification signals were deduced according to the geometrical parameters of EBCS-XCCD and physical optics. An example of calibrating spectra was presented with elliptical crystal of a-quartz (1 010,2d=0.852 nm ) for the 0.399~0.736 nm photon wavelength region. The spectrum intensity from laser plasma X-ray source was also obtained by the formula based on known the integrated reflectivity of the crystal, the transmission of foil and the responsivity of X-ray CCD photodiode to photons,results show that the good spectral resolution of laser-produced Al plasma is better than 1 000. The unfolded spectra by the method were compared with that of the reference [1], the results are basically identical. These data reported here indicate that this system is particularly suitable for the high-precision measurements of the spectral line profiles and positions in nonhomogeneous plasmas,and experimental results are superior to those obtained in earlier measurements, which demonstrates the EBCS-XCCD performance.