As a significant grain production base in China, the irrigation water requirements of large and medium-sized irrigation districts along the middle reaches of the Yangtze River play a crucial role in ensuring agricultural production safety. This study systematically analyzed the changes in irrigation water requirement characteristics of irrigation districts along the middle reaches of the Yangtze River. The main findings are as follows: During the study period, the proportion of major grain crops planted in the irrigation districts increased from 49 to 68%. Based on the daily-scale irrigation water requirement model constructed, the study revealed the characteristics of water supply-requirement imbalance in crops within the irrigation districts, with evapotranspiration showing a decreasing trend (987.42 mm/year) and irrigation water requirement slowly increasing (1,902.88 mm/year). The annual average total irrigation water requirement in the irrigation district was 34,331.10 × 104 m3, with a significant water shortage. This indicates that adjustments in agricultural crop structure and climate change have jointly shaped the irrigation water requirement pattern in the irrigation district.