Abstract: Aiming at the deformation problem of the condenser titanium tube of a nuclear power plant in China, the multi-phase flow CFD method was used to analyze the flow and heat transfer characteristics of the internal tube bundle module in different working conditions, and the stress of local titanium tube by finite element method. The research results show that when the unit stops temporarily in winter, the air cooling area of the condenser will be frozen. When the unit starts, Titanium pipes were damaged by ice moving due to the gravity and force of the flow field inside the condenser, caused large-scale deformation of the titanium tube around the air-cooling zone of the condenser.