In the construction of CSD transporting medium-coarse sand,it is difficult to determine the optimum construction parameters of transportation and the rotation speed of dredge pump unit.Aiming at the problem that the calculation accuracy of hydraulic transportation of non-uniform medium-coarse sand is insufficient by common calculation formulas at present,the calculation formula should be fitted-revised by actual construction parameters to realize the accurate calculation of construction parameters of slurry transportation.At the same time,by calculating and analyzing the operation power of the dredge pump unit,the low-power rotation speed of the dredge pump under the most economical transportation parameters can be determined.The characteristic of rotation speed is,under the given mud flow rate,concentration and total lift of mud pump unit,that the underwater pump adopts low speed and deck pump adopts high speed,which is conducive to reducing energy consumption in transportation construction.