Abstract: Microorganisms play an important role in regulating soil nutrient cycling. However, high concentrations of salt ions in saline-alkaline soils can significantly impact the life history strategies and community assembly mechanisms of microorganisms, thereby altering microbial community structure. These alterations reduce the abundance or activities of functional microorganisms, suppressing soil nutrient cycling and ultimately impairing soil ecosystem functions. Microorganisms can adapt to environmental stressors by adjusting their life history strategies and community assembly mechanisms. Through the evolution of survival adaptation mechanisms like intracellular accumulation of compatible solutes and regulation of intra- and extracellular ion homeostasis, microorganisms maintain osmotic homeostasis across cellular membranes to counteract osmotic stress in saline-alkaline soils. These processes ensure the functioning of nutrient cycling of carbon, nitrogen, phosphorus and sulfur, and modulate ecosystem functions. Therefore, we reviewed the variations of microbial composition, functional traits, life history adaptations, and survival mechanisms in saline-alkaline soils to provide a theoretical foundation and practical insight into the biological remediation of degraded saline-alkaline soils.