Capacitive differential pressure chip and preparation method thereof

The invention provides a capacitive differential pressure chip and a preparation method thereof, and belongs to the field of MEMS sensors, and the capacitive differential pressure chip comprises a sensitive film layer and two fixed polar plate layers. Grooves are formed in the two faces of the sensitive film layer, a boss is arranged in each groove, the height of each groove is larger than that of each boss, and a first electrode is arranged on the side wall of the sensitive film layer. The two fixed polar plate layers are symmetrically arranged on the two faces of the sensitive film layer, a metal coating is arranged on the side wall of each fixed polar plate layer, and a capacitor is formed by a gap between each metal coating and the boss of the corresponding sensitive film layer; each fixed polar plate layer is provided with a pressure leading hole and a conductive hole along the thickness direction; a second electrode is arranged on the face, away from the sensitive film layer, of each fixed pole plate la