Abstract: In order to realize rapid and safe field commissioning of the CPR1000 steam turbine control system, a simulation model of the steam turbine based on the RELAP5 code is established to replace the actual steam turbine equipment. The calculation results show that the errors between the calculated values of main parameters of the established steam turbine model and the actual operation data meet the requirements. The calculation results of main parameters under dynamic conditions such as linear load change, step load change and load rejection are consistent with the change trend of actual operation data, which indicates the established steam turbine simulation model can replace the actual CPR1000 steam turbine to connect with the control system and complete the qualitative field commissioning of the correctness of the control logic of the steam turbine control system.