The Fe90Ni6Cu4 precursor powder was prepared by chemical co-precipitation taken FeSO4·7H2O, NiSO4·6H2O, CuSO4·5H2O and NaOH as raw materials. The Fe90Ni6Cu4 precursor powder shape was majority stick, its diameter was about 10nm, length was about 100nm. The reaction conditions were that concentration of Fe2+, Ni2+ and Cu2+ mix solution was 0.1mol·L-1, NaOH solution concentration was 4 mol·L-1, the dropping rate of NaOH solution was 50 ml·min-1, the reaction temperature was 30°C, the pH value of the reaction end was 11, the stirring rate was 1200 r·min-1. The Fe90Ni6Cu4 alloy powders were obtained through hydrogen reduction of the Fe90Ni6Cu4 precursor powders. When the hydrogen reduction temperatures lower, it’s the reaction speed slower. When the reduction temperature was 800°C, the restore time needed to the 1200sec. The Fe90Ni6Cu4 alloy powder particle’ size was 200-500 nm.