A pressure sensor package includes a substrate providing a connection port, a support member mounted on the substrate by compression molding and having a gap cut through opposing top and bottom walls thereof to expose the connection port, a sensor chip mounted on the support member and electrically connected to the connection port, an encapsulating cover covered on the support member and defining therein an accommodation chamber that accommodates the sensor chip and a through hole that is disposed in communication with the accommodation chamber for the passing of an external signal therethrough to the sensor chip. Thus, the support member steadily carries the sensor chip and isolates stress arising from the external environment, thereby reducing stress interference with the sensor chip and enhancing the overall performance of the pressure sensor package.