The invention relates to a ceramic capacitive pressure sensor and a preparation method thereof, and belongs to the technical field of sensor preparation. The ceramic capacitive pressure sensor comprises a thick ceramic substrate and a thin ceramic substrate, the thick ceramic substrate and the thin ceramic substrate are bonded and fixed through a glass paste bonding layer, a plurality of grooves are formed in the side edge of the thick ceramic substrate, each groove is filled with an L-shaped conducting strip, the conducting strips and the grooves are conductively connected through elargol, and a bonding pad is further arranged at the groove position of the top of the thick ceramic substrate and used for being connected with the conducting strip to achieve the transition connection effect.According to the ceramic capacitive pressure sensor, the groove is cut in the side edge of the thick ceramic substrate, the groove is filled with the conducting strip, and the groove cavity is filledwith the conductive silver adhesive between the conducting strip and the groove, so that the ceramic capacitive pressure sensor is not influenced by air pressure, the groove cavity can be filled withthe conductive silver adhesive, meanwhile, visual detection can be carried out, and the output reliability of the sensor is obviously improved.