The invention discloses a shield electric motor for an oil-submerged pump and a preparation method therefor. The shield electric motor comprises a vacuum pump shell, a cable assembly, a stator assembly mounting cylinder sleeve arranged in the vacuum pump shell, a driving shaft, a rotor assembly mounted on the driving shaft, a stator assembly arranged in the stator assembly mounting cylinder sleeve, an upper end supporting base body assembly and a lower bearing base assembly, wherein the upper end supporting base body assembly and the lower bearing base assembly are arranged at the two ends of the stator assembly mounting cylinder sleeve, and a sealed cavity is formed in the stator assembly mounting cylinder sleeve; the rotor assembly is positioned in the sealed cavity; the stator assembly mounting cylinder sleeve comprises an inner cylinder sleeve, an outer cylinder sleeve, and a left end cover and a right end cover for fixing the inner cylinder sleeve and the outer cylinder sleeve together; the stator assembly in the stator assembly mounting cylinder sleeve is poured and sealed with epoxy resin; and the epoxy resin is poured and sealed through a resin pouring and sealing working table. The shield electric motor is simple in structure, high in insulation, high in safety, capable of eliminating an air-resisting phenomenon, long in service life, and convenient to process.