Leakage detection system

The utility model provides a leak detection system. The leak detection system comprises a main vacuumizing pipeline, a pre-vacuumizing pipeline and a detection device, the first end of the main vacuumizing pipeline is connected with the cavity, and the second end is connected with the vacuum pump; a swing valve and a molecular pump are sequentially arranged on the main vacuumizing pipeline from the first end to the second end; the first end of the pre-vacuumizing pipeline is connected with the cavity, and the second end of the pre-vacuumizing pipeline is connected to a pipeline between the vacuum pump and the molecular pump; a vacuum valve is arranged on the pre-vacuumizing pipeline; the detection device is connected to a pipeline between the vacuum valve and the cavity; the detection device comprises a detection pipeline and a detector; the first end of the detection pipeline is connected to a pipeline between the vacuum valve and the cavity, and the second end of the detection pipeline is connected with the