A package on package (PoP) package structure is disclosed, the structure includes at least two layers of carrier boards that are packaged and stacked in sequence, wherein chips are arranged on the bottom side of the carrier boards, a heat sink is arranged on the bottom side of a carrier board other than a layer-1 carrier board, a pad welded to a system board is arranged on the bottom side of the layer-1 carrier board, and a chip on a carrier board other than a top-layer carrier board is surface-mounted onto the heat sink adjacent to the chip. The heat sink increases the heat dissipation area of the chip, enhances the heat dissipation capabilities of the PoP stacked packages massively, breaks the bottleneck of the high-density integration and miniaturization of the PoP stacked packages, and enhances the packaging density of the PoP stacked packages.