In view of the difficulty of the CSD in dredging and transferring construction of the clay-sand mixed soil,we choose the cutter’s type applicable to this kind of soil in Bayuquan area based on the analysis.The research result and practical application show that the ESCO-3G cutter is suitable for the clay-sand mixed soil,which can improve the construction efficiency of the CSD and cut down the construction cost,so as to improve the profit of the project.