The invention relates to a sensitive 
chip of a 
pressure sensor, in particular to a hidden-type 
MEMS pressure sensor sensitive 
chip and a manufacturing method thereof. According to the hidden-type 
MEMS pressure sensor sensitive 
chip and the manufacturing method, the problem that component performance and service life of an existing 
silicon piezoresistive 
pressure sensor are not ideal is solved. The hidden-type 
MEMS pressure sensor sensitive chip comprises an SOI 
wafer component layer (1) and a glass substrate (5), wherein the SOI 
wafer component layer (1) is formed by the practice that a substrate layer of an SOI 
wafer is etched in an 
etching process based on a stopping layer, and the BOX layer of the SOI wafer is taken as the stopping layer. Four 
voltage dependent resistors of the 
Wheatstone bridge including R1, R2, R3 and R4, eight 
doping wires (3) and eight connection anchor points (2) are manufactured on the SOI wafer component layer (1). The hidden-type MEMS 
pressure sensor sensitive chip and the manufacturing method are reasonable in design, the manufacture hidden-type MEMS pressure sensor sensitive chip overcomes influences of external environment factors on a component circuit, the defect that component performance is reduced due to thermal mismatch of materials is eliminated, and service life of components is prolonged.