Biological soil crusts (BSCs) is a widespread ground living cover in arid and semi-arid areas, which serves an important ecological function in ecosystems of arid regions. To study its distribution regularity is the theoretical basis of scientific management and utilization of this resource. In view of this, this paper chose a typical slope in Liudaogou small watershed of Wind-Water Erosion Crisscross Region of the Loess Plateau, made a comprehensive survey and analyzed by using GS+ and the CANOCO statistical software, discussed the slope scale distribution characteristics of BSCs and its influencing factors. The results showed that: (1) the distribution of BSCs has an obvious spatial differentiation. In sand area, the BSCs mainly distributed widely and continuously, and their mean coverage is generally over 30%. While in loess area, the BSCs mainly shows a sporadic distribution pattern, and their coverage are generally below 20%; However, the spatial variation of the thickness and shear strength of BSCs are not significant, which indicates that it mainly depends on its development years. (2) Canonical correspondence analysis (CCA) showed that the distribution of BSCs has a close relation with soil, vegetation, ground surface humidity, slope and aspect ect. Among them, soil type has the closest relation with the distribution of BSCs, which can explain 20% of spatial variation of BSCs. The next is type of vegetation communities and topographic wetness index, and Artemisia desertorum Spreng land and Populus simonii Carr woodland are its most ideal growth environment. Some other environment factors such as slope, aspect and solar radiation also have some effects on the distribution of BSCs. On the whole, BSCs has an obvious topography, soil and vegetation community selectivity, and tend to develop in humid desert vegetation communities.