Abstract: Disclosed are anisotropic samarium-iron-nitrogen magnetic alloy powder and a preparation method therefor. The anisotropic samarium-iron-nitrogen magnetic alloy powder has a chemical formula of Sm2Fe17N3, and has a Th2Zn17 crystal structure. In the alloy powder, the granularity is: D90?5 ?m and D10?0.5 ?m, the average sphericity ?0.7, the coercivity Hcj?10 kOe, and the square degree Q?0.5. The preparation method includes: S1: mixing iron powder, samarium oxide powder and calcium granules uniformly; S2: placing the mixture into a rotating heat treatment furnace, adding high-temperature-resistant balls, performing vacuumizing, introducing a reductive diffusion protective gas, and heating a furnace body; S3: cooling the furnace body, performing vacuumizing, and introducing a nitriding gas; and S4: taking out and separating the cooled powder and balls, washing the powder, and drying the powder in a vacuum environment to obtain the anisotropic samarium-iron-nitrogen magnetic alloy powder.