A　two-dimensional　axisymmetric　fluid　model　was　employed　to　investigate　the　influence　of　varying　argon　volume　fraction　in　the　working　gas　on　the　propagation　characteristics　and　reactive　species　generation　of　pulsed　He　+　Ar　+　O2　plasma　jet.　The　results　demonstrate　that　at　an　argon　volume　fraction　of　10%,　the　Penning　effect　between　He　and　Ar　is　most　pronounced,　and　the　electron　temperature　and　electron　density　of　the　He　+　Ar　+　O2　plasma　jet　reach　their　maxima.　The　electron　temperature　in　the　upstream　region　of　the　jet　front　dissipates　more　slowly　due　to　Penning　ionization　between　helium　and　argon.　At　the　end　of　the　pulse,　higher—temperature　electrons　accumulate　near　the　tube　nozzle　in　a　triangular　distribution.　During　propagation　from　the　tube　into　open　air,　the　ionization　wave　of　the　He　+　Ar　+　O2　plasma　jet　evolves　from　a　hollow　ring　to　a　solid　bullet　shape,　with　the　highest　bullet　velocity　observed　at　an　argon　volume　fraction　of　10%.　The　densities　of　Ar+　and　Ar*　reach　their　maxima　at　argon　volume　fractions　of　10%　and　30%,　respectively,　while　the　densities　of　He+　and　He*　decrease　monotonically　as　the　argon　volume　fraction　increases.　Notably,　the　ozone　generation　efficiency　is　maximized　at　an　argon　volume　fraction　of　10%.　©　The　Author(s),　under　exclusive　licence　to　Springer　Science+Business　Media,　LLC,　part　of　Springer　Nature　2025.