A multi-chip package device with heat sink and a fabrication method thereof are proposed. At least one first chip and at least one semiconductor package are mounted on and electrically connected to a chip carrier. Then, a heat sink is mounted via an adhesion layer to the first chip and the semiconductor package. In addition, at least one hollow part extending through the heat sink is formed in an area of the heat sink free of contact from the first chip and the semiconductor package, in order to release thermal stresses produced from the heat sink. Thereby, the package device can be prevented from being damaged during the reliability test process, and a product yield is thereby promoted.