Physical mechanism of summer severe climatic high temperature and drought disasters in Sichuan and Chongqing area in 2006 are studied by using NCEP data from years 1970 to 2000 and year 2006. Comparing thermodynamic experiments with control experiments indicates that sensible heating caused the obvious strengthening of geopotential height and temperature rising of the Tibetan Plateau, and also has same effects on the Sichuan and Chongqing Area. Then it induced the plateau high to move eastward, and the subtropical high over the West Pacific to move westward, thus the two highs are strengthened at the same time. Dynamical analysis finds that the dynamic effect of the Tibetan Plateau is only one of the causes to bring about the disaster. The abnormal strong descending flow which controls the disaster area is jointly induced by the subtropical high over the West Pacific, the Tibetan Plateau high and the southward flow over north of the Tibetan Plateau. It is the sensible heat that plays the first important role to result in the disaster to sustain over a long period of time.