The present invention discloses a Micro-Electro-Mechanical System (MEMS) pressure sensor device and a manufacturing method thereof. The MEMS pressure sensor device includes: a substrate having at least one recess formed on an upper surface thereof, the recess defining a boss; a membrane, which is bonded to at least a part of the upper surface and at least a part of the boss, so that the at least one recess forms a cavity; at least one sensing unit, which is coupled to the membrane, for sensing deflection of the membrane; and an opening, which is formed on a lower surface of the substrate, and connects to the cavity.