Combining with the new east coastal city of Shaoxing road soft ground treatment works, the in-situ experiment of dynamic consolidation method combined with vacuum well point dewatering is carried out. Construction settlement, underground water level and excess pore water pressure are measured and analyzed in the experiment, and conduct static cone penetration and bearing capacity are tested after reinforcement. The results showed: High Vacuum Densification method can effectively reinforce deep saturated silt subgrade, can accelerate the dissipation of pore water pressure, shorten the construction period; and significantly improve the value and bearing capacity of foundation soil reinforcement after the effective reinforcement depth of 8m, treatment effect to meet the design requirements, which has a certain reference value for similar reinforcement deep saturated silt roadbed coastal areas.