Soil salinity is a major concern for both agricultural productivity and land degradation. In recent years, increasing attention has been given to managing saline soils, restoring degraded lands, and addressing growing global food demands under the impact of climate change. Rising salinity not only accelerates desertification but also degrades soil quality, disrupting key microbial processes, such as anaerobic ammonium oxidation (Anammox), and reducing overall microbial activities. The high diversity of soil microorganisms plays a critical role in ecological functions, including nutrient cycling and nitrogen transformation. The main objective of this study is to highlight changes in bacterial communities and their function under salt stress conditions. Furthermore, soil microbes can potentially be utilized to mitigate soil salinity and promote sustainable land use. Therefore, this review explores the impact of salinity on anammox processes and land degradation, as well as how increasing soil salinization may influence the functional diversity of soil microbial communities. The present research also focuses on interactions among microbial diversity and functions across various natural ecosystems. Understanding these mechanisms is vital for improving nitrogen use efficiency, reducing environmental pollution, and reclaiming saline-degraded lands for agricultural productivity. This review outlines future research directions and emphasizes the need for interdisciplinary collaboration among scientists and policymakers to develop effective soil restoration and management strategies.