In the current research, we propose a new method to synthesize Ni-Cu-Zn ferrite powder, using the steel pickling liquor and the waste solution of electroplating as the starting materials. It is found that the Ni-Cu-Zn ferrite powder prepared by the hydrothermal process from the waste solution showed the formation of cubic ferrite with a saturation magnetization (M-s) of 31 500 Am-2/g and an intrinsic coercive force (Hci) of 1536 Am-1, whereas upon annealing at 750 degrees C for 2 h, the M-s increased to 52 600 Am-2/g and the Hci reached 3406 Am-1. The toroidal specimen sintered at 950 degrees C for 2 h presented an optimum initial permeability (mu(i)) of 185 at 16.9 MHz, a maximum quality factor (Q) of 100 at 3 MHz. This useful technology can promote the recycling of industry waste solution and contribute to the preservation of the earth. Moreover, this technology can also decrease the manufacturing cost in the treatment of the industrial waste solution for the electroplating and steel industries.