The sample preparation method of Cadmium Zinc Telluride (CdZnTe) crystals based on traditional X-ray diffraction topography (XRT) is to grind and polish the test wafer to obtain a surface that meets the test conditions. As the size of single crystal wafers increases, the difficulty and time consumption of wafer grinding and polishing processing become higher, and it is also easy to cause wafer damage. To solve the above issues, a new method for preparing XRT samples has been obtained by studying the corrosion method of wafers after cutting and grinding. This sampling method can quickly remove surface damage from the wafer, obtain the wafer surface meeting XRT test requirements, significantly reduce sampling difficulty and shorten sampling time. The XRT image of the sample prepared by this method has uniform contrast and good signal-to-noise ratio. All types of crystal defects can be detected. This technology can be well applied to the subsequent screening and processing of large-sized cadmium zinc telluride wafers.