A method and a device for nondestructively detecting an elasticity of a viscoelastic medium are provided. The method includes: detecting a pressure applied to the viscoelastic medium by an ultrasonic transducer probe; in response to the pressure satisfying a predetermined condition, triggering detecting the elasticity of the viscoelastic medium; driving the ultrasonic transducer probe with a low-frequency vibration by a vibrator so as to produce an elastic wave in the viscoelastic medium; producing an ultrasonic wave by the ultrasonic transducer probe, and transmitting the ultrasonic wave to the viscoelastic medium; collecting an ultrasonic echo; calculating an elastic parameter of the viscoelastic medium according to the collected ultrasonic echo.