Abstract: Branches with same target produce redundant native code and exit code.A control flow identification based dynamic binary translation（DBT）code cache compression strategy is proposed to remove the redundant code and reduce DBT runtime memory space by extending dynamic generated translation blocks. Two extension methods, speculative and non-speculative, with branch characteristic are analyzed.The strategy identifies control flow with branch direction and offset, chooses extension method based on it,and compresses DBT code cache.The experimental results show that,the dynamic code cache size in QEMU based on this strategy could be reduced by 10%~40%.