Abstract: The present invention provides a rare earth hard alloy and a preparation method and application thereof. The rare earth hard alloy includes 6 to 15 wt % of a binding phase and the balance of a hard phase, wherein the binding phase includes 30 to 50 wt % of Ni3Al, 0.1 to 0.5 wt % of a rare earth element and the balance of Ni. According to the rare earth hard alloy provided by the invention, the Ni—Ni3Al-rare earth element (e.g., Ni—Ni3Al—Y)-based binding phase is strengthened by Ni3Al, and an ordered strengthening phase is formed and is diffused and distributed in the binding phase, such that the rare earth hard alloy has a better high-temperature oxidation resistance, a better room-temperature fracture toughness and a better high-temperature bending strength than a conventional hard alloy.