Abstract:Due to the polytrope and uncertainty of geological conditions,there are many risk ources in the construction of tunnel and underground projects,especially for subsea tunnel construction. Up to now,there is a proper method for safety evaluation of subsea tunnel construction. Based on the risk analysis,the risk sources have been identified. Combining with the experiences in the safe construction of tunnel and underground engineering,based on the classification of rock mass,the achievements in rock mechanics and measuring techniques,and the research experiences in safety evaluation,a safety evaluation system for subsea tunnel construction is established. The main relevant factors and their weight coefficients directly influencing the construction safety of subsea tunnel are given. Accordingly a system with six ranks from I to VI is put forward. The evaluation method put forward above has been applied to a practical engineering. The results show that the safety evaluation result is closed to the practical one.