Abstract: The present invention discloses a composite soft magnetic powder core and a preparation method therefor, which belong to the technical fields of soft magnetic materials and preparation thereof. An Fe/Fe3O4 shell layer is generated in situ on surfaces of iron powder particles through a controlled oxidation process, to prepare Fe/Fe3O4 composite soft magnetic powder having a uniform structure. The Fe/Fe3O4 composite soft magnetic powder is mixed with suitable amount of silicone resin, and prepared into a high-performance Fe/Fe3O4 composite soft magnetic powder core by using a powder metallurgy compaction process. Such magnetic powder core has a high density, a high magnetic conductivity, a high magnetic flux density, a low loss, and a high breaking strength, and is useful in a large-power and low-loss application scenario. The present invention has the advantages of being rich in raw material resources, simple in process and environmentally friendly, and being suitable for industrial production.