Xiong’an New Area is a state-level new administrative region established in 2017, and groundwater resources are an important source of water supply. Based on the comprehensive treatment of groundwater over-exploitation in North China, the groundwater resource status, groundwater dynamic change characteristics, and multi-factor influencing mechanism in Xiong’an New Area were studied under the influence of multiple water source allocation, ecological water replenishment in rivers and lakes, and restricted groundwater exploitation. Research provided a scientific basis for water resource allocation and ecological recovery in the new district. Results showed that: (1) From 2000 to 2021, the groundwater level in Xiong’an New Area showed a trend of first decreasing and then rising. Since water was transferred through the South-North Water Diversion Project in 2014, the shallow groundwater level has risen by 0.11m per year on average; (2) According to the random forest machine learning analysis, the groundwater level in Xiong’ an New Area was mainly affected by the amount of groundwater extracted (contribution rate 55%), precipitation (contribution rate 42%), and ecological water replenishment; (3) Numerical simulation method was used to analyze the change of groundwater level without considering the influence of precipitation. The rising groundwater level from 2019 to 2021 was mainly affected by precipitation, and the current average groundwater extraction was slightly higher than the number of recoverable resources. Transregional water resources such as the South-North Water Diversion Project must be fully considered to ensure the safety of urban water supply and sustainable use of groundwater resources.