Biological soil crusts (Biocrusts) are important components of dryland ecosystems, playing a crucial role in various ecological functions, including soil stabilization, nutrient cycling, soil moisture retention and preventing soil erosion. They exhibit significant spatial heterogeneity in distribution, which profoundly impacts their ecological functions. However, the distribution characteristics of biocrusts in existing studies are mainly described qualitatively, which limits the comprehensive assessment of their ecological functions. This study focused on biocrusts in rehabilitated grasslands across different precipitation zones of the Loess Plateau, China and aimed to fill this gap by quantifying their distribution characteristics. By conducting field investigations and advanced image processing techniques, we quantified the spatial distribution patterns and characteristics of biocrusts using landscape pattern indices. This approach allowed us to clarify the spatial distribution characteristics of biocrusts across varying precipitation zones, ranging from 200 mm to 550 mm. The results showed that (1) Landscape pattern indices were effective in quantifying the distribution characteristics of biocrusts. Biocrust cover in rehabilitated grasslands on the Loess Plateau varied from 47% to 73% across precipitation zones ranging from 200 to 550 mm. Significant differences were observed between these zones, with the average biocrust cover in the 200-250 mm precipitation zone (73%) significantly higher than in the 250-550 mm precipitation zone (52%). (2) The distribution pattern of biocrusts differed with precipitation zones. As precipitation increased from 200 to 550 mm, the distribution pattern of biocrusts transitioned from a matrix pattern to a coexistence of matrix and patches, and eventually to a patch-dominant pattern. (3) The patch characteristics of biocrust varied significantly among different precipitation zones. As precipitation increased from 200-250 mm to 250-500 mm, the number of biocrust patches tripled. Meanwhile, the largest and mean biocrust patch areas decreased by 42% and 49%, respectively, and the patch shape became more complex. Additionally, biocrust patches in the 450-500 mm precipitation zone tended to be nearly circular compared to other precipitation zones. (4) The distribution characteristics of biocrusts differed significantly across precipitation zones. The length and fragmentation of biocrust patches increased as precipitation increased. This study represents the first quantitative the patch characteristics and distribution patterns of biocrusts in different precipitation zones on the Loess Plateau, China. It provides a theoretical foundation for assessing the ecological functions of biocrusts. Moreover, it offers valuable scientific guidance for the restoration and management of dryland ecosystems, contributing to more effective conservation strategies for biocrusts.