Xray crystal characteristic parameters are the bases of identification of Xray crystal species and class, kinds of Xray crystal spectrometer fabrication, Xray lines intensity quantitative measurement and Xray monochromatic image diagnosis. On the automatic Xray diffractometer (XRD), based on stability and precision control of θ and 2θ goniometer, special plane crystal holder was made. Bremsstrahlung and CuKα line were attenuated for 5 orders by 40 μmthick Nickel filter, Xray sources was to be CuKα monochromatic source, and transmission power of filter was the criterion of CuKα monochromatic source. For Xray Pentaerythritol(002) plane crystal of Crystal lattice (2d) and integral reflective coefficient (Rc) of CuKα energy were calibrated, there are 2d=(0.87 425±0.00 042)nm, Rc=(1.759±0.024)×10－4 Rad respectively. This kind of experimental method is efficient and convenient on XRD in common laboratory. On XRD, other monochromatic Xray sources can be obtained by changing the material of Xray tube, and integral reflective coefficient of different energy will be obtained by the same way.