Abstract: A large power PWR core was designed. The burnable absorber reloading, the equilibrium cycle core design, reloading of the first and transition cycles were studied. The fuel management optimization code based on characteristic statistic algorithm (CSA) was used for global search efficiently. The core physics analysis code CPACT was used for core calculation. The cycle lengths of 18 months and 24 months were designed separately. The result shows that for each design, the basic design constraints are all satisfied and the equilibrium is reached quickly at the fourth cycle.