Abstract: The present invention provides a novel partial-pressure mass spectrometer calibration device, which is mainly composed of a fine adjustment valve, a piston pressure gauge, a sample preparation chamber, a plurality of high-purity gas cylinders, a capacitive film vacuum gauge, a first-stage sample inlet chamber, a second-stage sample inlet chamber, sampling chambers, a small hole, a calibration chamber, a separation gauge and air pumping systems, wherein the sample preparation chamber is connected with the piston pressure gauge and the capacitive film vacuum gauge; the sample preparation chamber is also connected with the plurality of high-purity gas cylinders which are connected in parallel via the fine adjustment valve; a plurality of sampling chambers with different volumes are connected in parallel between the sample preparation chamber and the first-stage sample inlet chamber; a plurality of sampling chambers with different volumes are connected in parallel between the first-stage sample inlet chamber and