Rare earth permanent magnet and preparation method and application thereof

The invention provides a rare earth permanent magnet and a preparation method and application thereof. The preparation method comprises the following steps: smelting a Sm < x > Zr < y > Fe < z > alloy ingot, and remelting and rapidly quenching the alloy ingot to obtain a quenched alloy belt with the crystallization degree of 40-60%; wherein the surface linear speed of a copper roller of the remelting and rapid quenching equipment is 40 m/s-60 m/s, x, y and z are the atomic percentage contents of Sm, Zr and Fe respectively, y is equal to 0-1.5, x: z is equal to 1: (8.75-12), x + y + z is equal to 100, and the quenched alloy strip is of a mixed structure comprising a SmFe9 phase and an amorphous phase; grinding and crushing the quenched alloy belt to obtain alloy powder; and the alloy powder is firstly subjected to nitriding treatment and then subjected to crystallization treatment. According to the preparation method provided by the invention, the crystallization degree of the quenched Sm-Fe alloy belt is cont