A method for preparing fan-out antenna packaging structure, includes: providing a carrier and a release layer structure; forming a single-layer antenna structure and a redistribution layer on an upper surface of the release layer; disposing a semiconductor chip electrically connected with the redistribution layer; forming a leading-out conducting wire on the redistribution layer at least on one side of the semiconductor chip; forming a plastic packaging layer wrapping the chip and the leading-out conducting wire; removing part of the plastic packaging layer to expose the chip and the leading-out conducting wire; forming an under-bump metal layer and a solder ball bump on an upper surface of the plastic packaging layer; removing the carrier and the release layer to expose the single-layer antenna structure; soldering a substrate on the solder ball bump; and forming a layer of cooling fins on a second surface of the semiconductor chip.