High viscosity silt soil strata have been often encountered in trenchless engineering. Great shear stress is needed to destroy the soil mass, thereupon many project accidents happened such as too large torque of drill pipe, difficult guided drilling and hole reaming with construction delay. In this paper, by the laboratory experimental study and the analysis on the mechanism molecular structure, a common disaccharide organic compound was introduced, which was applied in drilling fluid to effectively solve the high torque for drilling in viscosity silt soil strata.