The topographic critical model for the occurrence of erosion at gully head can effectively predict the conditions for the formation of erosion gullies, the depression formed by shallow landslide instability is also one of the ways of gully head formation. In order to explore the characteristics of the critical initiation model of shallow landslides, the rainfall-type shallow landslides in the Xiaolong mountain area of Tianshui City, Gansu Province was taken as the research project. We used area-slope relationship to construct the shallow landslide critical initiation model, and compared with the critical initiation model for typical erosion gully ephemeral gullies and permanent gullies located in the Loess Plateau. The effects of land use type, vegetation type and soil texture on the critical initiation model were also discussed. The results showed that: (1) The critical initiating model of shallow landslides was S=3.50A_s^-0.34, and its topographic threshold was 3.50, which was larger than ephemenral gullies (0.96) and permanent gullies (1.54) in the Loess Plateau. Shallow landslides in the study area generally occurred on steep slope area with thin soil layer, and the average slope (S=1.26 m/m) was higher than ephemeral gullies (S=0.35 m/m) and permanent gullies(S=0.46 m/m). The unit upslope drainage area (A=89.08 m²/m) was less than the ephemeral gullies(A=920.93 m²/m) and permanent gullies (A=1 129.82 m²/m). (2) The product of upslope drainage area and the square of the critical slope gradient (AS²) was used as an important energy index for gully formation. The AS² value of shallow landslide in the study area ranged from 269.1 to 5 703.2 m², with an average value of 1 772.97 m². The AS² value of ephemeral gullies in the Loess Plateau ranged from 4.74 to 892.66 m², and that of permanent gullies in 41 to 814 m². In terms of starting energy value, ephemeral gullies < permcnent gullies < shallow landslides. (3) Land-use type, vegetation type and soil texture had an effect on the initiation of shallow landslide by affecting the resistance, permeability and clay content of soil. Among different land use modes, agricultural land was the most vulnerable to erosion, followed by forest land. The erosion resistance of landslides near Pinus tabulaeformis forest was higher than those in Larix kaempferi forest. The results of this study provide a theoretical basis for exploring the initiation conditions of shallow landslides.