The utility model discloses a quick measuring device of water radon, include: continuous emanometer, sampling bottle and radon gas transfer system, continuous emanometer and sampling bottle connect into closed -loop through the radon gas transfer system, and aquatic radon concentration in the continuous emanometer of radon gas process radon gas transfer system entering, is calculated through radon concentration in measuring the gas return path with the degasification of water sample tympanic bulla under the effect of built -in pump to the emanometer in succession. The utility model has the beneficial effects of: simple structure, it is convenient to use, and sample measuring time is 30min, and measuring result is accurate reliable, can be used to the investigation and the research of water radon contents.