Abstract: Due to its tall terrain and strong thermal forcing, the Tibetan Plateau significantly influences on the Asian atmospheric circulation system and plays a crucial role in the source and distribution of water vapor as well as the energy transfer. This study employs the Dynamic Precipitation Recycling Model (DRM) to track water vapor pathways, identify the main water vapor source areas for the Tibetan Plateau during summer, and quantitatively calculate the contribution rate of each source. By comparing strong and weak plateau summer monsoon years, the dynamic control mechanisms and anomalous response characteristics of water vapor transport pathways are revealed. The results show that: (1) During plateau summer monsoon, water vapor transport trajectories are classified into three groups: the northwestern trajectory group (long-distance transport over Eurasia, entering from the north), the westerly trajectory group (mid-latitude water vapor, entering from the west), and the monsoon trajectory group (including three pathways: long-distance from the Indian Ocean, short-distance from the Arabian Sea, and short-distance from inland China). (2) The western source area was the largest contributor to precipitation (34.64%), followed by the local recycling source (23.08%) and the southwestern source (20.25%). The eastern source area contributed the least (1.69%). (3) During strong plateau summer monsoon years, precipitation in the central and eastern plateau increases significantly, primarily driven by long-distance transport from the ocean (Indian Ocean and South China Sea pathways). In contrast, during weak plateau summer monsoon years, the dominant moisture transport is via the northwestern path from the Eurasian continent. This study clarifies the influence of plateau summer monsoon on regional water vapor transport processes, and provides a theoretical and reference basis for a deeper understanding of the role of Tibetan Plateau in Asian water cycle and for improving water resource prediction in the Tibetan Plateau and its downstream areas.