Device for testing air tightness of telescopic bellows loop

The utility model mainly discloses a device for testing the air tightness of a telescopic bellows loop. The device comprises a vacuum generating device, a standard tube, a to-be-measured tube and two micropressure difference transmitters, wherein the standard tube and the to-be-measured tube are same in shape and are respectively provided with an air inlet pipeline, an air outlet pipeline and a taper joint, the taper joints are all connected with the vacuum generating device via vacuum negative pressure valves, and the air inlet pipelines and the air outlet pipelines are connected with corresponding micropressure difference transmitters via vacuum cut-off valves. The device can effectively test tiny leakages all over a breathing loop, effectively test breathing air passage obstruction caused by injection molding or bad assembly at the same time, and solve the problems of loop deformation and product reposition after a test.