To research the influence of the orientation of CdZnTe substrate to the morphology of HgCdTe film,which was epitaxied on CdZnTe substrates,the primary and the processed CdZnTe substrate were compared by director,and the surface morphology of HgCdTe film was studied.By tracing the change of crystal orientation of CdZnTe substrate during processing,the cause and solution of the orientation change were studied.It is found that the crystal orientation of CdZnTe crystal changes significantly during the processing after the initial directional cutting,while the large crystal orientation deviation will not occur after the rough grinding process with larger thickness reduction.Therefore,the redirected results of the rough grinded substrates can be used as the basis for further selection of the CdZnTe substrates to guarantee the quality of HgCdTe films.