Abstract: The X'Pert Pro MRD cradle can provide five motorized movements. The effects of sample position on the peak position and intensity of spectrum during the X-ray diffraction (XRD) test were studied. Results showed that the peak position of the spectrum would shift when the surface of the sample is lower or higher than the center of the optical path, while the peak intensity would not be significantly affected. The peak position would show a decreasing or increasing trend depending on whether the surface of the sample is lower or higher than the central position of the optical path. The peak intensity of spectrum would be affected by the thickest sample when samples with different thicknesses are placed horizontally for batch testing, while the change of peak position is not obvious.