Abstract: For one-off water seal of components "one-way" chest drainage device in the actual process of using the sealing function of accidental failure problem, with the component design and processing quality, the rationality of the related production technology as a research object, through to the device internal sealing surface and processing quality, one-way valve floating switch, seal diaphragm installation effect, the weight of the components of clean degree and so on has carried on the experiment and analysis, find out the chest drainage of water sealing device of the main causes of the one-way valve seal failure in, and sum up the corresponding improving methods according to the results of the experiments, and improve the one-way valve sealing performance.