The present invention relates to a P-type high-performance thermoelectric material featuring reversible phase change, and a preparation method therefor. The thermoelectric material has a chemical composition of Cu 2 Se 1-x I x , wherein 0 < x ‰¤ 0.08. The method comprises: weighing elemental copper metal, elemental selenium metal, and cuprous iodide according to the molar ratio (2-x):(1-x):x, and packaging them in a vacuum; raising the temperature to 1150-1170 °C in stages and performing a melting treatment for 12-24 hours; lowering the temperature to 600-700 °C in stages and then performing an annealing treatment for 5-7 days, the substances being cooled to room temperature in a furnace after the annealing treatment; and performing pressure sintering at 400-500 °C.
