Abstract: Based on the operation data from gas oil hydrotreating units, the impacts of excess hydrogen, recycle liquid ratio and stripping hydrogen on the operation of unit adopted continuous liquid-phase hydroprocessing technology are analyzed by simulative calculation. The calculation results show that a small amount of gaseous excess hydrogen in reactor can build up a relative high hydrogen partial pressure; the presence of recycle oil is helpful to reduce the rise of temperature along catalyst-bed; moreover, an appropriate amount of stripping hydrogen can dilute the H2S concentration in reactant significantly. Therefore, it is well founded that the functions of recycle hydrogen system in conventional hydrotreating unit are fulfilled by the continuous liquid-phase hydroprocessing technology, which indicates that the recycle hydrogen system in hydroprocessing unit might be canceled in future.