Investigating the shear strength characteristics of sliding zone soil is crucial for evaluating slope safety and stability. This paper discusses the shear strength characteristics of Lishi loess and N₂ laterite in the sliding zone under different influencing factors based on in-suit multiple shear tests, and the shear strength characteristics of Lishi loess were contrasted and analyzed based on field and laboratory tests. The results indicated a favorable correlation between the shear strength of soil samples and normal stress. The shear strength attenuation of clay-rich N₂ laterite was much larger than that of sand-rich Lishi loess with the increase of the shear stage. Importantly, the mutation points of the shear rate corresponding to the peak stress of soil samples were obtained, which can be used as a symbol to judge the transfixion of the shear plane. Moreover, the stress-strain characteristics of Lishi loess under the same normal load were diverse as a result of the different experimental methods, and the residual strength characteristics for the two tests also varied substantially. Notably, the Lishi loess in the field test has a more stable residual strength than the laboratory direct shear test conducted. The findings can aid in the comprehension of the mechanical behavior of loess and laterite on the Loess Plateau.