The invention provides a precise pressurization device for an aero-engine thin-wall part. The device comprises a device base, an upper press plate and a lower press plate which are perpendicularly opposite to each other, and an air-operated system; the upper press plate is fixed on the device base through a supporting rod, the supporting rod can move up and down along a supporting rod mounting hole in the device base through adjustment nuts, and a spring sleeves the portion, between the upper press plate and the device base, on the supporting rod; a pressure sensor is connected to the bottom of the lower press plate, the bottom of the pressure sensor is connected onto an air cylinder of the air-operated system through a lifting table of the air-operated system, and the pressure sensor is further connected with a display meter which is arranged on the device base; the air-operated system comprises the lifting table, the air cylinder, an air-operated circuit and an air source which are connected in sequence. According to the precise pressurization device for the aero-engine thin-wall part, the aim of precise pressure loading to the aero-engine thin-wall part is completely achieved, and the pressure precision meets the requirement.