Different dredged soil will affect the productivity of cutter suction dredgers，especially the silt with high density，large sand，local silty clay mass，mixed sand，and clay particles，which will cause difficult dredging of cutter suction dredgers.Based on the data of slightly dense-dense silt excavated by Tianqi cutter suction dredger，this paper analyzes the productivity and specific cutting energy and establishes the relationship among the characteristic index of typical dredged silt，productivity，and specific cutting energy.The result shows that there is a quadratic polynomial relationship between productivity and silt standard penetration number，and there is an exponential relationship between specific cutting energy and the standard penetration number.The productivity formula obtained is in good agreement with the actual engineering data，which can provide a reference for dredging similar soil.