The invention discloses an LNG immersed pump with long service life. A bearing consists of an inner ring made of high-carbon chromium deoxidized bearing steel, an outer ring made of high-carbon chromium deoxidized bearing steel, a rolling body made of high-carbon chromium deoxidized bearing steel and a holding frame made of a cryogenic service fluorine-based resin. The holding frame and the rolling body are arranged between the inner ring and the outer ring. The rolling body is located within the holding frame, which efficiently improves the abrasive resistance and low temperature resistance of the bearing under low temperature LNG, reduces deformation of the bearing, guarantees that the clearance of the bearing during working is in a normal range, increases the service life of the bearing and meanwhile increases the service life of the pump body. The rotor shaft is provided with a cylindrical seal sleeve. The seal sleeve is arranged within a leakage channel in a matching way. A plurality of circular grooves or circular teeth is arranged on the outer wall of the seal sleeve. A direct connection maze seal structure is formed between the circular grooves or circular teeth on the outer wall of the seal sleeve and the inner wall of the leakage channel. The pump has easy processing of a part, simple assembly, no friction, low power consumption, and long service life and is especially suitable for high speed sealing.