Abstract:[Objective] The influence of the soil water content on the rheological properties of the soil slurry was analysed to provide a scientific basis for understanding the flow law of the slurry and the prevention and control of mudflow in the Loess Plateau region. [Methods] Four main types of soil in the Loess Plateau were studied, and the effects of water content on the soil rheological properties were investigated using rheological oscillation shear tests. [Results] ① The storage modulus, loss modulus and shear stress of lou soil, cinnamon soil and dark loessial soil all decreased with the increase of soil water content (40%~80%). The shear stress reduced from 229.85, 193.38 and 96.46 Pa to 2.25, 2.65 and 2.32 Pa respectively. Under conditions of high water content (> 50%), the loess soil showed a strong strain overshoot. ② With increased shear strain, the storage modulus of the four types of soil slurry appeared in two plateau areas, showing a two-step yield phenomenon. With increased soil water content, the slurry changed from a two-step to a one-step yield. The first step of the yield was related to the destruction of the initial network structure, and the second step indicated that the slurry structure was completely destroyed. ③ When the soil moisture content was less than 50%, the fine soil particles increase the degree of flocculation by forming flocs, thus increasing the shear stress at the flow point of the soil slurry. When the moisture content was greater than 50%, the coarse particles in the soil increased the shear stress at the flow point by increasing the friction between the particles. [Conclusion] Soil rheological properties are not only related to soil properties but also significantly influenced by soil water content. Soils with a high fine particle content have a slurry that is more susceptible to flow under high-water-content conditions.