In this study, the surface processing of cadmium zinc telluride (CZT) substrates was studied, which revealed surface dislocation defects. The surface processing mechanism and influence of the process parameters on the surface of the CZT substrates, including mechanical grinding, mechanical polishing, chemical mechanical polishing, and chemical polishing, are presented. Moreover, three types of chemical etchants, Everson, Nakagawa, and EAg, which reveal dislocation defects on the surface of CdZnTe with different crystal orientations, were also investigated.