Soil cofferdam and steel sheet pile cofferdam are both commonly used cofferdam structures,when the two are used for comparison and selection of construction scheme,in addition to the plane layout,structural stability analysis and construction schemes,the project cost is an important factor to be considered in the construction scheme selection.To choose a more economical construction cofferdam scheme,this paper analyzes the influence of construction scheme,land requisition,main material supply and other aspects on the project cost by combining with an engineering case.The results show that when the waterway engineering is short of soil and unable to absorb the excavated soil after the cofferdam is demolished,the steel sheet pile cofferdam has the advantage of saving land and cost.For the waterway engineering with sufficient soil supply and the excavated soil can be absorbed after the cofferdam is demolished,the soil cofferdam can give priority to be used.