Abstract: Objective To analyze the impact of high standard farmland construction on soil fertility and accurately grasp the characteristics of soil fertility changes, so as to provide technical reference for more effectively improving soil fertility in high standard farmland construction. Methods Taking the high standard farmland project in Yuanyang County, Henan Province as the study area, based on field-measured data of SOM, TN, AP, AK and pH, combined with multi-temporal Sentinel-2 remote sensing images during key crop growth stages, the spatial distribution of soil nutrients was analyzed. Taking field measured soil data and multi-temporal NDVI as independent evaluation factors, the comprehensive soil fertility index was improved and calculated. On this basis, the quantitative and spatial variations of soil fertility before and after construction were monitored and analyzed to evaluate the effects of high standard farmland construction on soil fertility. Results 1) After high standard farmland construction, the contents of main soil nutrients including SOM, TN, AP and AK all increased to varying degrees, while soil pH remained stable at 7.6 – 8.0 with a slight decreasing trend. 2) The area of regions with high soil fertility index values (Grade 1 + Grade 2) rose by 12.53% compared with that before construction, while the area of low-value regions (Grade 4 + Grade 5) decreased by 27.65%. Conclusions High standard farmland construction expanded the area of high-fertility plots and reduced the area of low-fertility plots. It exerted a particularly significant improvement effect on soils with medium and poor fertility grades, and the overall soil fertility of the study area was elevated.