Objective To explore microbial resources suitable for the ecological restoration of saline-alkaline soils and elucidate their stress tolerance and plant growth-promoting traits, thereby providing a theoretical basis for biotechnology-driven sustainable agricultural development. Methods Plant growth-promoting rhizobacteria (PGPR) were isolated and screened from the rhizosphere soils of three representative halophytes—Tamarix ramosissima, Lycium ruthenicum, and Kalidium foliatum—growing in the Minqin Oasis, Gansu Province, northwestern China. Selected strains were taxonomically identified by 16S rRNA gene sequence analysis. Their functional traits were systematically evaluated, including nitrogen fixation, phosphate solubilization, and production of indole-3-acetic acid (IAA), exopolysaccharides (EPS), and siderophores. In addition, stress tolerance under salinity, drought, pH, and temperature gradients, as well as antagonistic activity against six common phytopathogenic fungi, was assessed. Results A total of 62 bacterial isolates were obtained, among which seven multifunctional PGPR strains (HL3, HL6, HL12, HG3, HG8, HG12, and HG24) were selected and identified as Priestia filamentosa, Bacillus atrophaeus, Pantoea endophytica, Peribacillus frigoritolerans, Bacillus aryabhattai, Bacillus subtilis subsp. stercoris,and Paenibacillus peoriae, respectively. All the selected strains exhibited at least two plant growth-promoting traits. Notably, strains HL6 and HG24 simultaneously possessed nitrogen-fixing ability, phosphate-solubilizing capacity, and the ability to produce IAA, EPS and siderophores, showcasing pronounced multifunctionality. Stress tolerance assays showed that strains HL3 and HL6 tolerated up to 12% NaCl, while HL3 and HG8 withstood osmotic stress equivalent to -20 bar. Most strains remained active under alkaline conditions (pH 9.0) and within a temperature range of 28-45 ℃. Antagonistic assays revealed that HL6 inhibited all six tested phytopathogenic fungi, and HG24 exhibited broad-spectrum antagonistic activity against five pathogens, with the strongest inhibition observed against Alternaria solani. Conclusion This study demonstrates that PGPR isolated from the rhizosphere of halophytes in arid regions possess diverse plant growth-promoting functions and strong stress tolerance. These multifunctional and resilient strains represent valuable microbial resources for saline-alkaline soil remediation and the development of locally adapted biofertilizers, contributing to sustainable agriculture and ecological restoration in arid environments.