The compact clay will form clay ball during pipeline hydraulic transport.The calculation of hydraulic transport of clay ball is a difficult problem in dredging field at home and abroad.Based on the theory of slurry transportation and construction data of cutter suction dredger,this paper studies the resistance characteristics of pipeline transportation of clay ball,and analyses the deviations that may occur when various theories of soil slurry transport are used to calculate the resistance characteristics of pipelines in clay ball.Based on the analysis results,the calculation formulas of clay ball transport have been studied which can be used as a reference for engineering and theoretical field.