Superfine magnetically soft alloy powder and preparation method thereof

The invention discloses superfine magnetically soft alloy powder and a preparation method thereof. Alloy elements of the alloy powder comprise, by mass percent, 2.0%-3.0% of Si, 4.0%-5.0% of Cr and the balance Fe. The method comprises the following steps that S1, three raw materials of Si, Cr and Fe are prepared in proportion and put into an intermediate frequency furnace to be smelted, and after the raw materials are molten to 1680-1700 DEG C to form molten steel, the molten steel is atomized through a water-gas combination method; and S2, after high-pressure water atomization, the powder is subjected to drying, screening, grading and blending, and the finished product magnetically soft alloy powder is obtained. The powder produced through the method is fine in granularity, controllable in oxygen content, low in impurity content, high in finished product yield, good in powder sphericity degree and excellent in powder magnetic performance; and meanwhile, the FeSiCr magnetically soft alloy powder is high in ma