Abstract： This paper introduces Professor WANG Hui's clinical experience in treating essential hypertension by method of dispelling dampness and unblocking the collaterals. Professor WANG Hui believes that essential hypertension belongs to the category of collateral diseases in Chinese medicine. The clinical etiology and pathogenesis of cold， dampness， heat， blood stasis and deficiency are complex. Combined with the climatic characteristics of the south of the Yangtze River，which is full of misty rain and still damp in sunny days， and based on the theoretical idea of “collateral is suitable for unblocking and supplementing”，and the method of dispelling dampness and unblocking the collaterals，the treatment is treated by stages and with both attack and supplementation，so as to achieve a dynamic balance state of unblock collaterals and qi and blood harmony.