The invention discloses an ultrasonic electric spindle with a hollow water-discharge structure. The ultrasonic electric spindle comprises a spindle shell, a spindle rotor, a hollow water-discharge rotary connector, a wireless electricity energy transmission module, a squirrel-cage type motor, a hollow water-discharge connection pipe and a hollow water-discharge energy converter; the spindle rotor is provided with a water conveying channel; and the hollow water-discharge energy converter is arranged at the head of the spindle shell and is connected with the water conveying channel through the hollow water-discharge connection pipe. According to the ultrasonic electric spindle with the hollow water-discharge structure, the structural design is ingenious and reasonable; water passes the hollow water-discharge rotary connector, enters the spindle rotor and is sprayed out from a tool head of the hollow water-discharge energy converter; the cooling effect is good, cutting heat is effectively improved, and the cutter service life is prolonged; meanwhile, scraps in a deep hole can be discharged out through a water current sequentially, and accordingly the problem of difficult scrap discharging during deep hole machining is solved; and thus, the advantage on the deep hole machining aspect is effectively improved, the machining efficiency, effect, precision and quality, the cutter service life and the like are greatly improved, the machining effect is good, the working stability is high, and wide popularization is facilitated.