A gas permeability testing device

The invention discloses a gas permeability testing device and relates to the technical field of material barrier property detection. The testing device comprises a vacuum cavity, a vacuum pump, a first pipeline, a second pipeline and a control system. The vacuum cavity is divided by a test sample into a test-gas cavity and a testing cavity. The testing cavity is communicated with the vacuum pump through the first pipeline. The test-gas cavity is communicated with the vacuum pump through the second pipeline. The control system is used for controlling automatic opening and closing of valves on a control pipeline, acquires pressure values and inputs the values into a computer. The testing device can test and analyzes gas permeability of a tube type sample according to ASME standards. Single-zone vacuum degrees are controlled independently by adoption of a plurality of the valves, so that flexibility is high. The testing device is simple in structure and reliable. A whole testing process is automatically controlled, thus reducing errors caused by manual operation.