Abstract: A short-duration heavy rainfall event occurred in northeast Qinghai Province from August 17 to 18, 2022, causing serious casualties and property loss in several cities (counties). In this study, the characteristics of atmospheric precipatable water (P_wv), water vapor transport and budget of this short-duration heavy rainfall process were discussed based on the hourly rain gauge records in the northeast region of Qinghai Province, water vapor dataset from ground-based Global Navigation Satellite System Meteorological Observing (GNSS/MET) and the ERA5 reanalysis data. The results as follows. (1) The evolution of Pwv was a good indicator for the occurrence and end of heavy precipitation. There was a sharp rise in P_wv 1~2 h before the heavy rainfall, continuing to reach its peak. While the dramatic decrease in P_wv indicates the end of the precipitation process. (2) Before the occurrence of heavy rainfall, the water vapor convergence in the study area increased dramatically, accompanied by an increase in the vertical ascending motion of the airflow at 500 hPa, which laid the foundation for the formation of heavy rainfall. (3) The upper westerly water vapor transport (16.03×10⁶ kg·s⁻¹) was the main water vapor transport channel during the heavy rainfall process. The improvement of water vapor conditions in the early stage of heavy rainfall in the northern part of the study area mainly depended on the low-level easterly and southerly winds water vapor transport. While in the southern part of the study area, in addition to the factors mentioned above, it also depends on the low-level northerly wind water vapor transport.