Issue　queue　is　a　critical　structure　in　the　pipeline　and　more　vulnerable　to　soft-error　strikes.　Reducing　soft　error　vulnerability　of　issue　queue　cannot　be　ignored　in　microprocessor　reliability　design.　Instructions　clog　in　issue　queue　caused　by　instruction　flow　mix　and　functional　unit　configuration　mismatch.　That　makes　the　soft　error　vulnerability　of　issue　queue　increases.　This　paper　proposed　a　vulnerability　mitigation　method　which　does　not　need　to　change　functional　unit　configuration.　It　adjusted　the　instruction　flow　mix　in　issue　queue,　reduced　the　waiting　time　of　instruction　in　issue　queue　to　reduce　the　architectural　vulnerability　factor.　The　experiment　result　shows　that　average　reduces　of　architectural　vulnerability　factor　are　2.8%　and　improvement　of　reliability-performance　is　4.9%.