Quantum　symbolic　execution　is　a　technique　for　generating　test　cases　for　quantum　programs.　At　present,　quantum　symbol　execution　only　mechanically　divides　the　test　case　space　continuously　according　to　each　conditional　statement　in　the　debugged　program,　without　considering　the　entire　expression　and　the　nesting　of　conditional　statements,　which　results　in　complex　quantum　circuits.　To　solve　this　problem,　this　paper　proposed　an　optimization　of　quantum　symbols.　First,　by　simplifying　the　relational　expression,　the　number　of　quantum　modules　was　directly　reduced,　or　the　number　of　quantum　modules　was　indirectly　reduced　through　the　substitution　of　values.　Second,　the　methods　of　simplifying　circuit　for　logic　AND　and　logic　OR　were　presented,　respectively.　Finally,　it　was　proposed　that　the　nested　conditional　statement　was　regarded　as　the　logic　AND　of　outer　layer　and　inner　layer　to　simplify　the　circuit,　and　optimize　the　division　of　the　test　case　space　in　the　quantum　symbolic　execution.　Results　show　that　this　optimization　method　reduces　the　cost　of　implementing　quantum　symbolic　execution　circuits,　including　the　number　of　quantum　gates　and　qubits.　©　2023　Beijing　University　of　Technology.　All　rights　reserved.