Based on the daily precipitation data of 54 national meteorological observation stations in North China in August from 1961 to 2015 and reanalysis data from the European Center for Medium-Range Weather Forecasts (ECMWF) from 2000 to 2015, this paper investigates the anomalous circulation patterns and causes of the extreme drought in August in North China. The results are as follows. The extreme drought events in North China show interannual variations. During the extreme drought years in North China from 2000 to 2015, there is an abnormal wave train structure of “-,+,-,+” in the geopotential height anomaly field at 500 hPa in the mid-high latitudes. There is a strong anticyclonic anomaly over the western Ural Mountains which makes the warm ridge move northward, the strong anticyclonic anomaly over Lake Baikal strengthens the upper-level ridge and enlarges its influence range at the same time, and such anomalous circulation situation impels the cold and dry northwest airflow in front of the upper-level ridge to be transported to North China. Western Europe is a key area for the wave activity flux in the mid-high latitudes of the Northern Hemisphere, where the surface temperature at 2 m presents a significantly increasing trend, and the vertical wave activity flux TNZ at 500 hPa corresponding to this key area also increases significantly. Due to the abnormal thermal forcing, EU wave trains are excited, low-level energy is transmitted upward, and high-level energy is dispersed outward, which strengthens the warm ridge over the western Ural Mountains, causing anomalous circulation patterns in the mid-high latitudes and frequent extreme drought events in North China.