The identification and estimation of construction risks of Bohai Strait tunnel are made by means of analytic hierarchy process (AHP) fuzzy comprehensive evaluation method, with the construction risks estimation of existing devised program of Bohai Strait tunnel as an example. The results show that the construction risk grade of Bohai Strait tunnel is grade Ⅲ. The key construction risks of Bohai Strait tunnel, including manufacturing of main bearing of tunnel boring machine (TBM), mud/water bursting and ventilation,are analyzed, and the countermeasures and problems to be solved are presented. The paper can provide reference for the construction program determination of Bohai Strait tunnel and for the planning,design and construction program of sea-crossing tunnels in the future.