Taking the land subsidence caused by groundwater exploitation in Cangzhou City as an example, based on the analysis of geology and hydrogeological conditions of the study area, a geological conceptual model of groundwater exploitation and land subsidence was generalized, setting up a corresponding coupled numerical model of three dimensional groundwater flow and one dimensional soil deformation. On the basis of the completion of identification and verification of model, we forecasted the change characteristics of groundwater flow field and the change trend of land subsidence from the end of 2025 to the end of 2010 under the current conditions of groundwater exploitation. The results show that the maximum cumulative land subsidence within the scope of Cangzhou City will be 475 mm at the end of 2025, the minimum value being 270 mm.