Abstract: EV-grade high-purity lithium sulfide and a preparation method therefor, including: A. mixing and well grinding a lithium source and a sulfur source to obtain a mixture; B. primary reaction: mixing the mixture with hydrazine hydrate in an inert atmosphere and reacting to obtain an intermediate slurry; C. secondary reaction: performing secondary reaction on the intermediate slurry in the inert atmosphere and drying to obtain a crude lithium sulfide product; and D. calcining and ball milling the crude lithium sulfide product to obtain the EV-grade high-purity lithium sulfide. The purity of the EV-grade high-purity lithium sulfide prepared by the method is above 99.9%, the whiteness thereof is above 80, and D50?15 ?m; the method is characterized by simple process operation, high safety, low energy consumption, low equipment requirements and low production cost; therefore, the method is suitable for industrial production.