A method for quantifying viscoelasticity of a medium includes: obtaining a position-time graph of vibration propagation after the medium is subjected to a vibration excitation, determining an angle with maximum signal energy in the position-time graph by using angle projection, where the angle with the maximum signal energy corresponds to a slope of the position-time graph and the slope of the position-time graph is the propagation velocity of the vibration in the medium. Since the propagation velocity of the vibration in the medium is related to the viscoelasticity of the medium, a viscoelasticity parameter of the medium can be quantitatively calculated after the slope of the position-time graph is obtained. The method does not need to select a feature point from the position-time graph to calculate the slope of the position-time graph, and can efficiently and accurately quantifies viscoelasticity of the medium.