This invention provides a plastic sealant for AC permanent magnetic submersible motor, its sealing process and application. The plastic sealant is composed of: epoxy resin, diluent, curing agent, and silicon micropowder. The process comprises: (1) preparing the plastic sealant; (2) placing the motor stator in the stator sealing mold, locating, and placing the rotor in the rotor sealing mold; (3) sealing; (4) curing. This invention can be used for sealing AC permanent magnetic submersible motor, permanent magnetic wind power generator, electrical appliance, capacitor, transformer and inducer. This invention can largely shorten the sealing time, and can improve the sealing efficiency of diving motor. The plastic sealant has such advantages as low viscosity, smooth pouring, simple process, high product smoothness, good heat conductivity, good insulation, good waterproof property, no pollution during production and usage, and no toxicity to human bodies, thus is suitable for mass production.