Abstract: Through the field investigation, it is found that there are some loess landslides located at the intersection of the southern tableland of Jingyang and Jinghe river. It is considered that the river action is the main triggering factor. The paper used field investigation, confining pressure-reducing triaxial compression shear test(RTC)on saturated Q₂ loess and numerical simulation to study the formation mechanism of landslides induced by river action. It is concluded that the shear strength of the soil is related to the stress path. The shear strength under triaxial compression shear of reduced confining pressure is smaller than that under the conventional triaxial shear. The soil is more susceptible to shear failure under the triaxial compression shear of reduced confining pressure. There are key blocks at the foot of the slope, controlling the overall stability of the slope. The role of river in inducing loess landslides is due to the continued lateral erosion of the river, resulting in the gradual collapse of the key blocks, ultimately leading to a slippage of the slope.