The study of the relationship between biodiversity and ecosystem functioning (BEF) is a hot topic in the field of terrestrial ecosystem ecology, and is of great significance for the efficient use and management of ecosystems. Furthermore, it plays an important role in the restoration of degraded ecosystems and biodiversity conservation. Alpine grassland is the main ecosystem type found in the Qinghai-Tibet Plateau. In recent years, progress has been made on species diversity and ecosystem functioning and their mutual relationship in alpine grasslands. This paper analyzes existing problems in the research of grassland biodiversity and ecosystem functioning in terms of the study of underlying ecological processes and the impacts on ecosystem multi-functionality under global change. The effects of different grassland types, grassland degradation, grazing disturbance, simulated climate change, mowing, fertilization, enclosure, and replanting on the relationship between biodiversity and ecosystem functioning in alpine grasslands are also thoroughly reviewed in this paper. Moreover, deficiencies and future research directions of alpine grassland BEF are identified: carrying on the BEF research of alpine grasslands based on the functional diversity of species, comprehensively considering the effects of abiotic factors such as resource supply levels, disturbance intensity and scale, and environmental fluctuation on the relationship between species diversity and ecosystem function, and paying attention to the effect of scale and element coupling on BEF research of alpine grasslands under global climate change. Finally, based on research progress and conclusions of BEF in alpine grasslands, we put forward suggestions to improve the utilization rate of alpine grassland resources and biodiversity conservation, including strengthening grazing management, protecting biodiversity, improving governance of degraded grasslands, maintaining biodiversity function, strengthening innovation and protection concepts and enhancing ecosystem functioning that has been seriously weakened by climate change and human disturbance.