【Objective】Soil salinization imposes combined stresses of high salinity and phosphorus (P) deficiency, thereby severely constraining plant growth. Puccinellia distans is a salt-tolerant halophyte; however, the response mechanisms of its rhizosphere microbiome to salt stress, particularly concerning organic P mineralization functional genes, remain poorly understood. This study aimed to clarify the response patterns of organic P mineralization functional genes in the rhizosphere of P. distans and to identify the underlying mechanisms. It is hypothesized that salt stress affects these microbial functional genes indirectly by altering soil physicochemical properties and root traits, which subsequently reshape root exudation patterns. 【Method】A controlled pot experiment was conducted using P. distans under five NaCl-induced salt stress gradients: control (0 g·kg-1), light (2 g·kg-1), moderate (4 g·kg-1), severe (6 g·kg-1), and extreme (8 g·kg-1). After 30 days of continuous salt stress, rhizosphere and bulk soil samples were collected. Metagenomic sequencing was employed to determine the relative abundances of key genes involved in organic P mineralization, including phnM, 3-Phytase, phnI, phnL, phoA, phoD, phnH, and phnW. Analysis of variance (ANOVA), Pearson correlation, random forest models, and partial least squares structural equation modeling (PLS-SEM) were used to identify the major drivers and causal pathways underlying changes in these genes under salt stress.【Result】Salt stress significantly altered the relative abundances of phnM, 3-Phytase, phnI, phnL, and phoA genes in the rhizosphere, whereas only phoA and phnW responded significantly in bulk soil; phoD and phnH were not significantly affected. In the rhizosphere, 3-Phytase, phnI, phnL, and phoA exhibited a unimodal pattern, initially increasing and then decreasing with increasing salt stress. Under severe stress, the abundances of phnM, phnI, phnL, and phoA increased by 24.7%, 34.5%, 52.9%, and 34.7%, respectively; while 3-Phytase increased by 8.0% and 7.2% under moderate and severe stress. In bulk soil, phoA increased by 26.0% and 17.5% under severe and extreme stress, while phnW decreased by 13.3% under extreme stress. Correlation analysis showed that in the rhizosphere, soil electrical conductivity (EC) and salinity were positively correlated with several genes, whereas root traits were generally negatively correlated with them. Among root exudates, quinones were positively correlated with phoA, 3-Phytase, phnL, and phnM, whereas terpenoids and stilbenes showed negative correlations. PLS-SEM further indicated that salt stress enhanced soil EC (path coefficient = 0.882, P<0.001), which inhibited root exudation (terpenoids, stilbenes, quinones; path coefficient = -0.79, P<0.001), subsequently influencing the abundances of rhizosphere organic P mineralization genes (path coefficient = -0.49, P<0.05) (R²=0.72). In bulk soil, salt stress primarily affected phoA by altering soil properties and inhibiting exudates (R²=0.82).【Conclusion】Salt stress differentially impacts the relative abundances of organic P mineralization genes in the rhizosphere and bulk soil of P. distans, with the rhizosphere exhibiting a more pronounced adaptive response. By altering electrical conductivity and simplifying root architecture, salt stress further reshapes root exudation patterns, which in turn regulates the relative abundances of rhizosphere microbial organic P mineralization genes, thereby contributing to plant P acquisition strategy. These findings provide molecular insights into the salt tolerance mechanisms of P. distans and offer a theoretical basis for the sustainable use of saline-alkali soils.