Preparation method of soft magnetic composite material powder

The invention relates to a preparation method of soft magnetic composite material powder, which comprises the following steps: 1) preparing metal magnetic material powder, including but not limited to water atomization, gas atomization, mechanical crushing, reduction and carbonylation methods; 2) preparing a coating solution, and adding phosphoric acid and hydrogen peroxide into a solvent; 3) coating: uniformly mixing the metal magnetic material powder and the coating liquid; and 4) carrying out hot air drying, centrifugal drying or distillation on the coated powder to separate the coating liquid which does not participate in the coating reaction from the metal magnetic material powder. The coating process is optimized, the process design is more reasonable, hydrogen peroxide is added into the conventional phosphoric acid coating liquid as a strong oxidant, so that the surface of the prepared metal magnetic material powder has a phosphate layer and an oxide layer, the coating integrity is improved, the eddy-c