Low-temperature ultrasonic vibration fatigue experiment system

The invention discloses a low-temperature ultrasonic vibration fatigue experiment system. The low-temperature ultrasonic vibration fatigue experiment system comprises a piezoelectric transducer and an ultrasonic signal generator. The electric energy input end of the piezoelectric transducer is electrically connected with the alternating current signal output end of the ultrasonic signal generator, and the mechanical vibration output end of the piezoelectric transducer is connected with a test piece. A cryogenic box is further included and is of a closed box body structure, the test piece is located in the cryogenic box, a cooler is further arranged in the cryogenic box, a cooling device is further arranged outside the cryogenic box, and the cooling device is connected with the cooler through a pipeline. The cooler is of a spiral-coil-shaped structure, and the reciprocating direction of the test piece is located on the axis of the spiral-coil-shaped structure. A convection fan arranged in the cryogenic box is