Abstract: As global climate change intensifies, drought has emerged as one of the most severe abiotic stresses that restrict plant growth and threaten food security and ecological health. The colonization and functions of rhizosphere microorganisms play a pivotal role in promoting plant growth and enhancing crop drought resistance, their symbiotic relationships with plants can assist plants in combating drought through various mechanisms, presenting broad application prospects. Therefore, this paper systematically reviews the impacts of drought stress on plant rhizosphere microbial communities, analyzes its direct and indirect regulatory effects on microbial functions, and delves into the regulatory networks of plant drought resistance systems mediated by rhizosphere microorganisms, as well as the mechanisms of plant-microbe interactions and ecological adaptation strategies under combined stresses. Finally, addressing the current research limitations, such as insufficient understanding of the mechanisms underlying the stable colonization of microbial communities in field conditions, a lack of means to identify and regulate key root exudate signals, and the complexity of microbial functional responses under combined stresses, this paper further proposes specific research directions for the future. These include focusing on the artificial construction of stable functional microbial consortia, analyzing key signaling molecules in root exudates, and exploring the formation mechanisms of soil microbial “drought memory”. The aim is to provide a scientific basis for exploring new approaches to enhance plant drought resistance and lay a theoretical and practical foundation for sustainable agricultural development.