Bridge deep water foundation is usually in the environment of deep water, torrent and complicated geographic condition. The double-wall steel cofferdam is widely applied in bridge deep water foundation due to that it is of characteristics of high structural strength and good waterproof performance. On the basis of analysis of practical engineering, the topics such as the structure of cofferdam, treatment of cofferdam edge foot under inclined rock base, cofferdam stability analysis, laying out of anchorage system and the method to determine the bottom sealing concrete thickness are systematically discussed. It is anticipated that it is of some help to the design and construction of bridge deep water foundation in our country.