An elastic couple barring apparatus (i.e., an elastic couple rotor turning gear) is a special tool to drive a rotor by elastic couple for adjusting a shafting center of a vertical hydroelectric generating set and other rotating devices. The elastic couple rotor turning gear is characterized in that an elastic support is mounted on a frame of the driven device, a casing being connected to the elastic support, a casing cover being firmly fixed on the casing, a speed reducer and an electric motor being installed on the cover, an output shaft of the speed reducer extending into the casing under the casing cover, the output shaft having a pinion gear mounted thereon and meshed with a gear body of a bull gear positioned in the casing, the bull gear being connected to a shaft coupling through parallel keys via a key seat or an upright post, and the shaft coupling being fixed on a rotor of the driven device. The advantages of the invention is that the structure is more reasonable, the concentricity may be adjusted more conveniently, the elastic connection makes operation easy and vibration small, deformation caused by suspending arms is eliminated, and operation's accuracy and precision are improved because the gears may be meshed and operated smoothly.