Based on the hydrogeological conditions of the Huahai irrigation area in the Shule River Basin, and focusing on the relationships between groundwater recharge, runoff, and discharge, a hydrogeological model and a groundwater numerical model were established. The models were identified and calibrated through fitting of the groundwater levels over the past ten years. On this basis, the trend of groundwater level changes in the forthcoming 20 years and the influencing factors were predicted. According to the results, the groundwater level slightly increases under an exploitation intensity of 3. 505 2 million cubic meters per year, and significantly decreases under an exploitation intensity of 20. 098 6 million cubic meters per year, with the greatest decreased level being six meters. Intense exploitation of groundwater can lead to the continuous decline of the groundwater level in the irrigation area. The southeastern part of the study area in particular will be significantly affected, which will cause a series of ecological and environmental problems.