Abstract ： Research purposes ： Long subsea tunnel of metro has the characteristics of long length， deep depth，large span of sea segment， much structural percolating water， particularly important for operation safety and so on. And its structural percolating water and fire - fighting waste water all flow to the tunnel bottom，making great request on the design of drainage pumping station. Therefore，it is extremely important for the safe operation of long subsea tunnel of metro to research design and implement a set of safe， efficient，stable，reliable and economic system of drainage pumping station. Research conclusions ： Combined with the actual situation of subsea tunnel project of rail transit line 3 in Xiamen，and comprehensive analysis of its factors of drainage category， drainage method， displacement and difficult point of the design of drainage pumping station， the following conclusions are drawn ：( 1 ) According to the geological conditions of subsea tunnel project，and combined with similar project experience，the preliminary estimate the structural percolating water is 2 500 m3/d. ( 2 ) Through the scheme comparison， determine the scheme of drainage system to set up two drainage pumping station and promotion once，and briefly introduce the design of drainage pumping station. (3) Select water pump and pipe with good anti - corrosion and compression performance，ensure the stability and safety of drainage system and drainage pumping station. (4 ) It has the reference value for other design of drainage pumping station in long subsea tunnel of metro.