Leakage detecting device and detecting method

A leakage detecting device, comprising:

• a detecting bin having a cavity, the detecting bin being provided thereon with a material-loading port which is in communication with the cavity, and the detecting bin being further provided thereon with a blocking component for opening or blocking the material-loading port, the material-loading port being configured for enabling a piece to be detected to be placed into the cavity or enabling it to be taken out of the cavity;
• a vacuum generator being in communication with the cavity, a first switch valve being connected between the vacuum generator and the detecting bin and configured for enabling the vacuum generator to be in communication with or disconnect from the cavity, the vacuum generator being configured for extracting gas from the cavity;
• a clean gas generator being in communication with the cavity, a second switch valve being connected between the clean gas generator and the detecting bin and configured for enabling the clean gas generator to be in communication with or disconnect from the cavity, the clean gas generator being configured for delivering clean gas to the cavity;
• and
• a leakage detector being in communication with the cavity, a third switch valve being connected between the leakage detector and the detecting bin and configured for enabling the leakage detector to be in communication with or disconnect from the cavity, the leakage detector being configured for detecting gas composition in the cavity.