Salinity is a major challenge for plant growth, but Populus euphratica, a species native to desert regions, has a remarkable ability to tolerate salt stress. This study aimed to explore how salinity affects the rhizosphere microbiome of P. euphratica, focusing on diversity patterns, assembly mechanisms, network characterization, and the functional roles of specialists and generalists under salt stress conditions. The findings revealed that increased salinity enhances the complexity of the rhizosphere microbial network and the diversity of bacterial specialists. Specialists demonstrated a wider range of environmental adaptation and played a pivotal role in species interactions within the microbial network. Notably, salinity stress altered the structure and assembly of plant rhizosphere specialists, facilitating functional compensation and potentially augmenting the health of P. euphratica. This research offers critical insights into the microbiome dynamics of P. euphratica under salinity stress, advancing the understanding of specialists and generalists in the rhizosphere.