In a soft ground treatment project in Lianyungang, vacuum preloading is applied for strengthening the thick foundation which is mainly silt. The result appears very well and the bearing capacity of surface silt layer increase to over 70 kPa. This paper introduces the technology design, main construction technique and construction control. The effect of foundation treatment is ensured by the construction monitoring and test after completion. It is shown that the vacuum preloading method has many advantages for reinforcing silt foundation, such as good strengthening effect, short construction period, safe construction, and remarkable economic benefit, etc. Thus this method is worthy of popularizing in the coastal area of Lianyungang.