The development trend of a marine low-temperature deep-well pump is that the marine low-temperature deep-well pump is reliable at low temperature, necessary net positive suction head is low, efficient and energy-saving effects are achieved, and maintaining is convenient. According to the current status and the development trend, the structural design is broken through for the SCW low-temperature deep-well pump, a high-pressure self-tightening structure design is adopted, and magnetic suspension bearings are adopted. New material, such as high polymer material, is used so that the characteristics of safety, reliability, corrosion and leakage resistance and vibration and noise reduction of the marine low-temperature deep-well pump can be enhanced. In detail, a multi-stage impeller structure is adopted for achieving high lift, a mature inclined outlet deep-well pump hydraulic model is adopted, and a pump inlet is matched with an inducer, so that an expected hydraulic performance is achieved; a stainless steel casting, a stainless steel shaft, a PTFE sealing element, a graphite sliding bearing and other materials are used for being adaptive to the low-temperature environment below 104 DEG C; a mechanical seal cavity is matched with a booster, meanwhile, the gas pressure reduction effect of an upper sliding bearing is used so that it can be guaranteed that pumped liquid does not leak outwards in the high-pressure operation process of the pump, and safety can be guaranteed; a shutdown seal design is adopted so that the pumped liquid can not leak outward in the maintaining process of the pump, and then environment safety can be guaranteed. Pipe segmenting, pipe flange connection and shaft hard coupler connection are used for reaching the 5 m-22 m depth below the liquid.