With the global climate change and aggravation of human activities,groundwater systems especially groundwater dynamics, have undergone profound evolution. In terms of the interaction between the changing environment and the groundwater circulation system,Mann-Kendall trend test,grey correlation analysis and variance analysis of contrast coefficients are used to study the dynamic characteristics of groundwater in a changing environment with monitoring data of depth of the monitoring wells, temperature,precipitation,evaporation,artificial extraction and land use date in Qian'an County from 2000 to 2015. The results show that climate change and human activities are the main factors affecting groundwater depth. In the past 16 years,the depth of confined water in the study area increased significantly,while unconfined water changed little. Climate change and human activities are the main external driving factors for unconfined and confined water dynamics respectively while the thickness of the aquifer itself is an intrinsic factor controlling the dynamic response degree of the confined water. Meanwhile the response mechanism of groundwater depth in arid and semi-arid plain area under changing environment is proposed.