Abstract: The CFX software was used for the simulation and analysis of thermal-hydraulic characteristics of the water-cooled first wall of dual-cooled waste transmutation blanket (DWTB) in fusion driven subcritical system (FDS). Water in the typical operational condition of PWR was used as the coolant in this calculation. The calculation was carried out on a partial model of the first wall, in which coupling of heat transfers between solid and fluid was considered. Focus is placed on the temperature distribution of first wall structure, temperature distribution and pressure drop of the coolant at different wall heat fluxes and coolant flow rate. The calculation results show that when the inlet speed of water ranges from 1 m/s to 5 m/s, maximum temperature of the structure is 16 K to 91 K lower than when the structure is cooled by helium under typical operational conditions. Difference between maximum and minimum temperature of the structure is also 12.2% to 49.5% lower. The results show that the water-cooled system can meet the thermal-hydraulic requirements of the first wall under steadystate conditions.