In order to study the dynamic response characteristics of the soil around the pile under impact load and the reasonable values of soil dynamic parameters, dynamic triaxial tests were conducted on the muddy soil in Foshan using the SPAX-2000 dynamic -static true triaxial system. The response law of surrounding pressure, vibration frequency and frequency to dynamic Shear stress, liquefaction stress ratio, damping ratio and dynamic modulus of soil under impact load. The results show that: (1) The variation law of soil dynamic shear stress shows that the dynamic shear stress increases with the increase of confining pressure or vibration frequency, and decreases with the increase of vibration frequency. The surrounding pressure varies from 100 kPa to 400 kPa, the dynamic shear stress decreases from 67.1% to 45.2%. The dynamic shear stress at a frequency of 10 Hz is higher than that of 1 Hz by 44.3% to 72.6%. The surrounding pressure, vibration frequency and number of vibrations have a great influence on the dynamic strength of soil. (2) The variation law of dynamic modulus of soil parameters shows that the dynamic modulus of each deformation stage (initial modulus, average loading modulus, maximum loading modulus, and unloading modulus) is significantly affected by surrounding pressure and vibration frequency. The dynamic modulus increases with the increase of vibration frequency or confining pressure. (3) The variation law of soil damping ratio shows that the damping ratio decreases approximately linearly with the increase of confining pressure. When the confining pressure varies from 100 kPa to 400 kPa, the damping ratio is reduced from 0.285 to 0.153, and the vibration frequency has no obvious effect on the damping ratio. The research results can provide reference for the design of pipe piles, dynamic parameters for high-strain test analysis or similar projects.