The improvement of reliability is a key problem to be solved in the research and development of the domestic control system of the heavy-duty gas turbine. Hardware redundancy is an important guarantee for enhancing reliability of the control system, which can realize fault tolerance in function. Its cost is lower than repair. It has occupied a dominant position in industrial application. However, the development of domestic control system of the heavy-duty gas turbine is still at the early stage. Hence, the research on its reliability is almost blank. This article analyzes redundancy strategy of the domestic NuCON control system of the heavy-duty gas turbine, which uses Markov model accordingly to formulate the reliability model. The probabilistic model checker PRISM is utilized to calculate and test the reliability model quantitatively. The simulation shows that the unavailability of minimum hardware configuration of the NuCON control system is 1. 616×10 -4 , which meets the design requirement of system reliability. Meanwhile, the quantitative effects of different repair time, different system structure and different system scale on the unavailability of the system are compared and analyzed.