<p>It is important to study the nonlinear propagation mechanism from meteorological drought to hydrological drought, and to quantify the drought propagation thresholds, so as to provide important theoretical guidance for the early warning, prevention and mitigation of drought propagation in the context of global warming. This study takes the Jialing River basin as the research object, based on the meteorological and hydrological data in the basin from 1972 to 2017, adopts the standardized precipitation evapotranspiration index (SPEI) and the standardized runoff index (SRI) to characterize the meteorological droughts and hydrological droughts, respectively, and identifies the drought events by combining with the travel theory, and reveals the temporal and spatial droughts by the rotated empirical orthogonal function (REOF) and center of gravity migration. Further, the Copula function is used to construct the joint distribution of meteorological and hydrological drought characteristic variables, and the conditional probability of drought propagation is analyzed by combining with Bayesian network, and the threshold of drought propagation is determined. The results show that: (1) the spatial and temporal variability of meteorological drought in the Jialing River basin is significant, and can be divided into three typical modes with different drought characteristics; (2) the center of gravity of drought has been concentrated in the middle and southern part of the basin for a long time, but some years show anomalous migration, and the spatial distribution is shifted from dispersed to centralized; (3) the probability of propagation of meteorological to hydrological drought decreases significantly with the drought class, and the meteorological drought duration that triggers a moderate hydrological drought is 4.2&#xa0;days, and the threshold for the meteorological drought to be spread is 4.2&#xa0;days. threshold is 4.2&#xa0;months, and the intensity threshold is 4.1.</p>