Chip packaging structure and preparation method thereof

The invention relates to the technical field of chip packaging, and discloses a chip packaging structure and a preparation method thereof. The preparation method comprises the steps of providing a substrate; a transfer layer is arranged on the surface of one side of the substrate; a plurality of chips are arranged on the transfer layer, each chip is provided with a first surface and a second surface which are oppositely arranged, and the first surface is connected with the transfer layer; forming a sacrificial layer on the second surface of the chip; forming a plastic package layer covering the sacrificial layer and the chip on the sacrificial layer; removing the substrate and the transfer layer; arranging a rewiring layer on one side of the first surface of the chip; thinning the surface of one side, deviating from the rewiring layer, of the plastic packaging layer to expose the sacrificial layer; removing the sacrificial layer to expose the second surface of the chip, and forming a groove on the second surf