The evolution of land use in the Yellow River floodplain serves as an intuitive manifestation of regional ecological and environmental changes. Clarifying the laws of its spatiotemporal evolution and landscape patterns is of practical significance for optimizing regional land resource allocation and maintaining ecological security. In this study, the Ningxia reach of the Yellow River floodplain was taken as the study area, and the dynamic changes of land use and the evolution characteristics of landscape patterns were quantitatively examined by comprehensively applying methods including land use dynamic degree, transition matrix and landscape pattern indices, based on Landsat series remote sensing imagery from 2000 to 2020. The results indicated that during the study period, significant changes were observed in the land use structure and spatial pattern of the floodplain: cultivated land exhibited a trend of "increase followed by decrease", water bodies showed a trend of "decrease followed by increase", forest land shrank continuously, and construction land and unused land expanded significantly; The comprehensive land use dynamic degree reached 0.73 %/a, and the periods of intense land use change were identified as 2005—2010 and 2015—2020. The bidirectional conversions between cultivated land and water bodies, as well as between cultivated land and grassland, were found to be the most active transition pathways. At the landscape level, the Contagion Index (CONTAG) declined from 62.35 % to 59.07 %, and the Shannon''s Diversity Index (SHDI) increased from 1.18 to 1.25, indicating that landscape connectivity was diminished and fragmentation was intensified. The fundamental law that land use change in arid floodplains is driven by the dual forces of water resource constraints and policy regulation was revealed, providing a scientific basis for ecological conservation and optimized management of land resources in the floodplains of the upper Yellow River.