An underwater electric swim-assisting shoe comprises a plastic shoe outsole, a metal show sole from, a sole metal plate, a propulsion motor, a waterproof storage battery, a motor frame net cover and a battery protecting cover. A plurality of sole frame bolts and nuts are fixed on the metal shoe sole frame, the plastic shoe outsole after being positioned by injection and an electric swim-assisting vamp are assembled to form a shoe boot, the sole metal plate is fixed on the metal shoe sole frame by using the nuts, and the propulsion motor and the waterproof storage battery are fixed on the sole metal plate; after the motor frame net cover and the battery protecting cover are fixed on the metal shoe sole frame, underwater sundries can be prevented from tripping and winding propulsion propellers, and the underwater electric swim-assisting shoe can be worn to walk on shoals; when the underwater electric swim-assisting shoe is worn to move underwater, two feet are vigorously merged to push a sole triggering switch to act or press an electric shoe waterproof manual switch, in this way, the propulsion propellers on the propulsion motor can be controlled to rotate to push a human body to advance underwater. The underwater electric swim-assisting shoe is especially suitable for underwater sports, underwater exploration and navy special forces to use.