Tiny leakage amount measuring device and method

The invention provides a tiny leakage amount measuring device and method. The device comprises a closed water tank containing water and air, a water pipe, a first communication pipe, a pressure gaugeand a processor, wherein the bottom of the closed water tank is communicated with the bottom of the water pipe, and the pressure gauge is used for detecting the pressure of the bottom of the water pipe; a first communication hole is formed in a side wall of the closed water tank, the first communication hole is communicated with a to-be-detected gas leakage end through the first communication pipe, the first communication hole is located between the top of the closed water tank and a water line of the closed water tank, and a first valve is arranged on the first communication pipe; and the processor is electrically connected with the pressure gauge and is used for calculating the leakage amount of the to-be-detected gas leakage end according to the change of the pressure detected by the pressure gauge. Compared wi