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In this paper,agar gel is used as matrix to investigate ultrasonic propagation characteristics in viscoelastic medium containing bubbles.In this paper,the acoustic attenuation measurement experiment is based on acoustic detection technology,and the influence of bubble on ultrasonic propagation in agar gel is studied by transmission method.First,we explored the basic properties of agar gel,namely,the rate of water loss and the rate of cooling.Based on this,we explored a new method of injecting bubbles.Secondly,the influence of non bubble factors,namely,slurry separation and external pressure,on the sound attenuation of pure agar gel and bubble agar gel was investigated.It was found that the phenomenon of separation and external pressure had no significant effect on the propagation of ultrasonic waves in bubble agar gel.Then,the influence of bubble factors,namely bubble radius,number of bubbles and spacing of bubbles,on the attenuation of sound is explored.The ultrasonic attenuation test of bubble agar gel is carried out at 1 MHz and 3 MHz ultrasonic field.The finite element simulation model of viscoelastic medium containing bubbles is built based on the finite element method.The propagation of ultrasonic wave in bubble gel is simulated by using viscoelastic control equation and wave equation.Compared with the experimental results,the effects of bubble radius and bubble spacing on sound attenuation are further discussed.The test results are in good agreement with the simulation analysis results,and it is found that:（1）The attenuation of ultrasonic wave in bubble agar gel is composed of the attenuation of sound scattering and the absorption and attenuation of sound.When the bubble is small,the sound energy gain due to the resonance of bubbles is greater than the attenuation of the sound energy in the changing direction,so the attenuation effect of bubbles on the sound is mainly the absorption of air to the sound.With the increase of bubble,the enhancement effect of bubble resonance on sound energy decreases,and the energy consumed by its resonance increases.At the same time,the increase of scattering area changes the direction of more sound energy,so the increase of sound attenuation is larger and larger.（2）When the number of bubbles is certain,the sound attenuation gradually increases with the continuous increase of bubble spacing.This is because the smaller the bubble spacing is,the more obvious the bubble interaction is,the stronger its resonance scattering ability and the stronger its scattering effect on sound are.The sound energy in the sound field has more gain,making the overall attenuation smaller than other spacing.With the continuous increase of bubble spacing,the interaction between bubbles approaches zero,and its scattering attenuation characteristics are close to a single bubble.At the same time,with the extension of distance,the sound energy is gradually lost in the process of passing through the bubble,so that the sound energy is not enough to make it have such a strong sound scattering effect from the second bubble,the resonance scattering effect of bubbles is not obvious,the sound gain is smaller,and the total attenuation is increased.（3）The sound attenuation of the bubble agar gel and the 1 MHz group of the simulation group is higher than that of the 3 MHz group,because the attenuation of ultrasonic wave in the bubble medium will decrease with the increase of frequency.（4）The attenuation of sound wave in bubble agar gel is composed of sound scattering and sound absorption.When the attenuation of acoustic absorption is constant,the effect of bubble spacing on acoustic scattering is obvious.The increase of spacing can cause more attenuation to sound waves.The first spacing plays a major role in the attenuation of scattering,and the larger the first spacing,the higher the attenuation of sound.The ultrasonic attenuation test and finite element simulation model of bubble viscoelastic medium established in this paper provide a useful reference for the ultrasonic test and simulation process of the change of gas type and bubble distribution state.