Diode test module for detecting leakage current and test method thereof

The invention discloses a diode test module and a test method thereof. The invention discloses a substrate with a first conductive type and an epitaxial layer which is formed on the substrate and has a second conductive type. A well-type region with a first conductive type is formed on the epitaxial layer, a first heavily doped region and a second heavily doped region with a second conductive type are electrically coupled to the first input/output end and the second input/output end and are theoretically formed in the well-type region, and isolation grooves are formed in the well-type region to provide electrical isolation. When an operation voltage is input, the detection unit provided with the third heavily doped region and the fourth heavily doped region is arranged on the current conduction path between the first input/output end and the second input/output end, and whether leakage current is generated or not is detected by arranging the detection unit, so that the detection efficiency is improved under t