Based on NCEP/NCAR reanalysis data and other conventional observation data, the abnormal characteristics of meteorological factors during an extremely heavy rainfall process in 2016 were analyzed. The results showed that the extremely heavy rainfall was a direct result of atmospheric circulation anomalies. The 500 hPa subtropical high was stronger than the climatic mean, which was conducive to the strengthening of water vapor transport, leading to stronger southerly normalized anomaly. The 850 hPa strong vortex development and 200 hPa shunting area formation contributed to the vertical uplift anomaly. By further analyzing the abnormal meteorological factors over the extremely rainfall sites, we found the absolute values of precipitable water, K index and 850 hPa divergence were higher than the climatic mean values for 1.5σ, and also higher than upper quartile of historical data. Finally, synoptic conceptual model and quantitative configuration diagram of abnormal meteorological factors were built based on above researches.