The machine adopts the Japanese Cosmo air differential pressure leak detector as the main tester. The machine has two stations. One station detects four assemblies, the other station loads and unloads four assemblies, and the two stations rotate for loading and unloading detection. The two ends of the air-conditioning pipe product are blocked, and the tooling composed of thin cylinder is adopted for rapid clamping. The principle of the instrument uses the high-precision differential pressure sensor to sense the standard chamber and the measured chamber respectively. When the measured chamber leaks, the diaphragm bends to the leakage chamber, and the product is judged to be qualified or not through the quantitative analysis of the computer. PLC is used as the central control, which can detect the leakage of a single product or a variety of products at the same time. The application of this special machine improves the reliability of products and is one of the necessary equipment of pipeline supporting factory.