The importance of Helium estimation in the gas test stage of saturation diving equipment system and the relevant contents of saturation diving gas test are analyzed. According to the test contents and requirements, the formula calculation of Helium consumption in the saturation diving system test stage is summarized and exampled with a real ship, the estimation method and estimation value of test Helium are clarified, and the feasibility of optimizing the test scheme is further discussed to reduce the selection of test gas schemes. The research content can be used as an important reference during the similar saturation diving ship construction.