Abstract: The saline-alkali soils in Inner Mongolia are generally faced with the shortage of nutrients such as nitrogen and phosphorus and significant salinization, which seriously affects agricultural productivity and ecological environment. To cope with these challenges, the study aimed to isolate and screen a variety of indigenous microalgae with excellent physiological properties in the saline-alkali land of Inner Mongolia, so as to provide biological resources for bioremediation of the saline-alkali land. Fifteen soil samples were collected from the saline-alkaline land on both sides of the Yellow River in Ordos City, and 21 strains of cyanobacteria were isolated and purified. After the preliminary growth performance evaluation, 10 algae strains with nitrogen fixation and strong carbon abilities were screened, and then their salinity-alkali tolerance and drying recovery performance were evaluated. The experimental results showed that under moderate and heavy saline-alkali conditions, algal strains No.6 and No.7 showed excellent biomass production and resistance, and both of them had particularly outstanding drying recovery capacity. In addition, the algal strains showed significant phosphorus solubilization capacity in both inorganic and organic phosphorus solubilization experiments, suggesting their potential for improving soil phosphorus use efficiency. The study concluded that algal strains No.6 and No.7 have important practical and applied value as biological resources with wide application prospects for saline-alkaline land ecological restoration and agricultural production.