A compressor leakage detector includes a water tank, an elevator platform, a control panel, and a pressure testing unit. The elevator platform is disposed in the water tank to rise and drop vertically. The operating panel of the control panel has a human-machine interface, indicators, and pressure gauges. The pressure testing unit in the control panel uses an intake pipe to connect to several branch pipes that in turn connect to the compressors in the water tank. Each of the branch pipes connects in series to at least one intake EM valve and at least one exhaust EM valve. A pressure sensor is interposed between the intake EM valve and the corresponding compressor.