In order to prevent and control electromagnetic pollution, it is urgent to develop effective electromagnetic shielding materials. In this paper, The Fe_73.2Si_16.2B_6.6Nb₃Cu₁ alloy was designed and amorphous ribbons were prepared. After high-energy ball milling, amorphous alloy powder was obtained. The effects of ball-milling time on soft magnetic properties, microstructure, morphology and electromagnetic wave absorption properties of alloy powders were studied. The results showed that the crystalline phases α- (Fe, Si) was formed after ball milling, which improved the soft magnetic properties. The maximum saturation magnetization was 137.94emu/g. The morphology of the amorphous alloy powder was elliptical and the minimum average particle size is 8.42μm. The alloys showed excellent electromagnetic absorption performance. The loss mechanism of electromagnetic waves was mainly magnetic loss. After ball-milling for 50h, the amorphous alloy powder had the best electromagnetic absorption performance. The minimum reflection loss was -42.26dB at the frequency of 4.57GHz, and the maximum effective absorption bandwidth (<-10dB) was up to 5.78GHz when the thickness of the absorber was 2.5mm.