[Objective] The effects of different amendment measures on soil water and salt content， organic matter， nutrients， and microbial communities in saline-alkali soil of the Qingtongxia irrigation area in Ningxia Hui Autonomous Region were analyzed， in order to provide scientific support for improving saline-alkali land in this area， thereby further to promote food security， improve land resource use efficiency， and facilitate sustainable agricultural development. [Methods] A field experiment on saline-alkali soil improvement was conducted in the Qingtongxia irrigation area， with nine treatments established. The main treatment types included the addition of organic and inorganic materials， microbial inoculants， and different tillage practices. [Results] ① Except for T₉ （where maize roots were 70 cm from the drip irrigation belt）， soil water content in the 0—40 cm soil layer significantly increased under the other treatments. Among these， T₅ （film mulching） showed the greatest increase， with its surface soil water content increasing by 35.59% compared with the control T₁ （no amendment application， no mulching， and no deep ploughing）. The pH value and total salt content in the 0—40 cm soil layer generally decreased across all treatments. The greatest reductions were observed in T₃ （phosphogypsum + natural humus + nitrohumic acid） and T₅， with pH value decreasing by 0.27—0.37 and salt content decreasing by 27.36%—41.82%. ② In the 0—20 cm soil layer， all treatments except T₉ significantly increased soil organic matter and nutrients compared to the control. The increases in organic matter， alkali-hydrolyzed nitrogen， available phosphorus， and available potassium were 3.13%—20.66%， 3.50%—127.50%， 5.05%—115.06%， and 5.06%—105.86%， respectively. T₃ showed the most significant increase. ③ The richness and diversity of the soil microbial communities significantly increased. T₃ and T₅ treatments notably increased the relative abundances of dominant bacterial genera Microbulbifer and Pseudomonas， as well as the dominant fungal genus Mycena. In all treatments， bacterial functional genes were mainly associated with amino acid metabolism， carbohydrate metabolism， and energy metabolism. The major fungal types were saprotrophic， symbiotic， and pathogenic. Soil under T₅ and T₇ （deep plowing + film mulching） had a higher abundance of beneficial symbiotic fungi. [Conclusion] The combination of film mulching with organic and inorganic amendments can significantly reduce soil pH value and total salt content， increase organic matter and nutrient content， and enhance microbial richness and diversity， demonstrating significant effectiveness in improving saline-alkali soil in the Qingtongxia irrigation area.