The invention discloses a method for microscopic preparation of a hexagonal phase bismuth telluride crystal. The method comprises the steps that Ge-Sb-Te amorphous films are prepared on substrates capable of characterizing microstructure or testing electrical properties, and Ge-Sb-Te compounds are selected as the main materials of heterostructures; preparation of amorphous thin films with high content of germanium by magnetron sputtering or molecular beam epitaxy thin film preparation; the prepared amorphous film is subjected to high temperature annealing treatment and protected under an argonatmosphere or a vacuum to form a hexagonal phase crystal structure; pretreatment of annealed hexagonal phase crystal samples. The TEM is used to characterize the structure of the pre-treated hexagonal phase crystal sample, or the electrical performance is tested by an electrical test platform, that is, the microscopic preparation of the hexagonal phase bismuth telluride crystal is completed. Themethod combines the mainstream film preparation method, facilitates the observation of microstructure characterization and performance characterization, and is simple and easy to operate with high feasibility.