Abstract: The radiation damage evolution of nuclear reactor materials significantly impacts its performance, and the evolution spans multiple orders of magnitude of time and space. A recently developed method, spatially resolved stochastic cluster dynamics, has been shown to be useful for simulating nuclear materials’ radiation damage behavior. It overcomes the limitations of traditional cluster dynamics method in defect types and computational complexity and can consider the spatial dependence of defects. Based on summarizing the basic principles of spatially resolved stochastic cluster dynamics, the implementation and key technologies of the self-developed large-scale parallel spatially resolved stochastic cluster dynamics program MISA-SCD1.0 were discussed. It is then applied to simulate the precipitation of rich-copper (Cu) clusters in the reactor pressure vessel model allies to verify the program’s correctness and test the parallel performance. The results show that MISA-SCD1.0 can obtain the Cu precipitate process consistent with the experimental results and similar simulation results. It also has high parallel efficiency and good scalability.