The　coupling　calculation　of　transport　and　depletion　usually　adopts　traditional　predict-correct　(PC)　burnup　method　in　PWR　fuel　assembly.　However,　the　method　results　in　the　calculation　error　because　of　its　assumption.　In　order　to　improve　the　accuracy　of　burnup　calculation,　the　modified　PC　burnup　method　was　studied　and　high-order　PC　burnup　method　which　corrected　the　microscopic　reactivity　was　improved.　Corresponding　code　was　developed　to　verify　and　analyze　these　burnup　methods　with　some　benchmarks.　The　results　indicate　that　new　methods　improve　the　calculation　accuracy　under　the　premise　of　insuring　calculation　efficiency.　©　2017,　Editorial　Board　of　Atomic　Energy　Science　and　Technology.　All　right　reserved.