围堰是水工建筑物修建时的挡水安全保护屏障，在水工建筑物修建完成后，围堰就需按时拆除。由于围堰拆除是电站导流洞过流的标志性工序，关系到后期电站的建设。因此，围堰拆除爆破只能成功，不能失败，否则进行二次处理极为困难，后果不堪设想。介绍了乌东德水电站右岸导流洞出水口围堰，论述了围堰及岩埂拆除的施工难点，优化选用拆除方案，对围堰及岩埂实施控制爆破,成功完成了出口围堰及岩埂拆除。

Cofferdam is the water retaining and safety protection barrier when hydraulic structures are built. After the construction of hydraulic structures, the cofferdam needs to be removed on time. Removal of cofferdam is a symbolic procedure of overcurrent in diversion tunnel of power plant, which is related to construction of power plant in later period. Therefore, cofferdam demolition blasting can only be successful, otherwise secondary treatment is extremely difficult and the consequences are unimaginable. This paper introduces the outlet cofferdam of diversion tunnel on the right bank of Wudongde Hydropower Station, discusses the construction difficulties in removing cofferdam and ridge, optimizes the selection of removal scheme, implements controlled blasting for cofferdam and ridge, and successfully completes the removal of outlet cofferdam and ridge.