Preparation method of amorphous composite magnetic powder core

The invention provides a preparation method of an amorphous composite magnetic powder core. The method comprises the following steps: modifying the surface of amorphous magnetic powder, generating a compact and uniform MgZnFe2O4 insulating coating layer in situ, and carrying out secondary insulating coating on the magnetic powder of which the surface is coated with MgZnFe2O4 by adopting resin to form a double-layer insulating coating layer. The amorphous magnetic powder particles subjected to insulation coating of MgZnFe2O4 are good in dispersity, the resistivity of the composite amorphous magnetic powder can be greatly improved, the loss of a magnetic powder core is effectively reduced, and meanwhile the direct-current bias characteristic of the composite amorphous magnetic powder is improved; moreover, due to the existence of the MgZnFe2O4 insulating coating layer, in the heat treatment process, even if the organic insulating material is heated and decomposed, the magnetic powder particles can still be subj