Abstract: Biological soil crusts (BSCs) are mixtures formed by the cementation of soil surface particulate matter, plant and microbial communities, and play an important role in elemental biogeochemical cycling in special environments. This thesis outlines the composition, types and succession processes of BSCs, briefly summarized four functional properties of BSCs, analyzed the research progress in the role of BSCs on phosphorus biogeochemical cycling in alpine ecosystems, and discussed the processes and mechanisms of BSCs affecting phosphorus cycling. From the perspective of the role of alpine BSCs on phosphorus effectiveness enhancement, a technical pathway for the rapid development of alpine bare land soil and vegetation is proposed to provide a reference for alpine ecosystem restoration.