The invention discloses a measurement method and a measurement device of viscoelasticity of a medium and relates to the field of measurement. The measurement method includes the steps of: 1) acquiring an ultrasonic echo signal of the medium with excitation of shear wave; 2) matching the ultrasonic echo signal with an ultrasonic echo signal sample stored in an ultrasonic signal data set, thus determining the viscoelasticity of the medium, wherein the ultrasonic signal data set is determined according to ultrasonic echo signal samples generated by a plurality of medium samples, having different viscoelasticities, respectively with excitation of at least one shear wave. The embodiment is based on the ultrasonic signal data set, wherein the ultrasonic echo signals are searched and compared, so that the method can acquire the measurement result of the viscoelasticity of the medium without performing motion estimation and character point selection; in addition, the method is greatly reduced in calculation load and is significantly increased in measurement speed.