Abstract: In order to realize the localization of large-scale LNG submersible pumps, a series of key technologies were researched, including overall structure design, key component design, strength analysis, material selection, hydraulic model design optimization, rotor dynamics analysis and axial force balance design. Then, the first large-scale LNG submersible pump (rated flow rate 430 m3/h and rated head 256 m) was successfully developed. Its hydraulic performance test was completed and its LN2 low temperature performance was also tested at low-temperature testing bench. The variable flow running performance test and the long-term reliability running performance test were performed on the prototype at Zhejiang LNG terminal. It is indicated that the prototype runs smoothly, and its noise and vibration values meet the design requirements. Its low-temperature materials are selected and designed rationally with good low-temperature mechanical property. The prototype is advantageous with good safety guarantee performance and strong reliability. Its operating parameters reach the design goals. The success of this project marks that China has fully mastered the technologies of large-scale LNG submersible pump, filling domestic technology gaps. And besides, the technical level of domestic LNG equipment is increased significantly, and the procurement cost and the late overhaul and maintenance expense are reduced considerably. This equipment is of great value in popularization and application.