A manufacturing method of a nanometer hexagonal sheet-shaped bismuth telluride thermoelectric material orderly comprises: a tellurium bismuth mixing process, an adjusting process, a sealing heating stirring process, and a purification process. The tellurium bismuth mixing process comprises: preparing a mixture of Bi and Te with a mol ratio of 2:3, and dissolving the mixture in an organic solvent to obtain a mixed solution; the adjusting process comprises: adding NaOH and polyvinylpyrrolidone to adjust the shape and size of the product; the sealing heating stirring process comprises: heating and performing heat insulation of the product under a sealing and stirring condition; the purification process comprises: purifying the product by centrifugation, cleaning, and drying. The design of the invention not only prepares the nanometer hexagonal sheet-shaped bismuth telluride thermoelectric material with a controllable product shape, but also is few in process links, short in period, low in energy consumption, and low in cost.