Device and method for improving leakage rate detection precision

The invention discloses a device and a method for improving leakage rate detection precision. The device for improving the leakage rate detection precision comprises a compact and rigid sealing cavity, a first differential pressure sensor and a second differential pressure sensor are connected to the sealing cavity, the measuring range of the first differential pressure sensor is smaller than that of the second differential pressure sensor, and the sealing cavity is communicated with a detected cavity. One of the high-pressure input end and the low-pressure input end of the first differential pressure sensor is connected to the sealed cavity, and the other one is connected to the measured cavity. According to the invention, the pressure of the detected cavity is not directly detected, but the pressure difference between the detected cavity and the sealing cavity is detected by the pressure difference sensor with a smaller range, and then the leakage rate data is obtained through the change of the pressure dif