Abstract:To improve water application efficiency of farmland irrigation, water application efficiency of farmland irrigation in Fengtai County from 2018 to 202l was calculated based on the actual measurement and survey data in Fengtai County, combined with the actual production situation in the local area. The influencing factors and changing laws of water application efficiency of farmland irrigation were discussed and analyzed from four aspects: resource conditions, the overall scale of the irrigation area, engineering input, and management measures. The results showed that the continuous promotion of the supporting facilities and water-saving renovation projects in the irrigation area, the promotion of water-saving irrigation technology, and the strengthening of irrigation area management could effectively improve the irrigation water application efficiency in Fengtai County. The research results are of great significance to the development of water-saving irrigation areas and a water-saving society and have certain reference values for the formulation of county-level water-saving imri-gation plans.