Check dams are known to support sediment retention and erosion control for water and soil conservation; however, their hydrological role in perched groundwater recharge remains mechanistically unresolved. To address this gap, we integrated water level monitoring, iodide-bromide tracer tests, water table fluctuation (WTF) calculations, and cumulative sum (CUSUM) analysis to investigate perched groundwater dynamics associated with check dams in the Yangjuangou Catchment of the Loess Plateau in China. We find that the perched groundwater levels exhibit distinct spatiotemporal variability, with recharge-dominated areas located in the middle and tail sections above check dams and discharge-dominated zones occurring near the check dam head. Iodide-bromide tracer tests identified both vertical and lateral subsurface water movement, with rates of 6.4 cm & sdot;day-1 and 7.1 m & sdot;day-1, respectively. Recharge totaled 207.3 mm, representing 48.4% of the annual rainfall, and included contributions from both infiltrating precipitation and lateral water inflow. Recharge response lagged rainfall by approximately 9 days and followed a nonlinear relationship. Collectively, these findings support development of a new conceptual model focused on the "precipitation-driven-perched groundwater" relationship, challenging the traditional view of check dams as static storage. They reveal the formation, migration, and precipitation response mechanisms of perched groundwater, establishing its role as "dynamic hydrological regulators". This process-based framework enhances assessment of groundwater recharge, lateral connectivity, and hydrological regulation within check-dam systems in semi-arid environments.