The　photon-assisted　electron　transport　properties　through　a　parallel-coupled　tri-quantum-dot　system　are　studied　using　the　time-dependent　non-equilibrium　Green＇s　function　theory.　When　a　time-dependent　external　field　irradiates　a　parallel-coupled　three-quantum-dot　system,　the　interaction　between　photons　and　electrons　provides　more　novel　transport　characteristics.　The　average　current　can　be　switched　between　zero　and　non-zero　by　controlling　the　level　of　the　time-dependent　external　field,　indicating　that　an　optically-controlled　quantum　switch　can　be　realized.　The　time-dependent　external　field　makes　it　more　advantageous　for　the　system　to　be　designed　as　a　magnetic-controlled　quantum　switch.　If　the　magnetic　flux　and　Rashba　spin　orbit　coupling　interaction　are　simultaneously　considered,　the　average　current　exhibits　a　spin　polarization　phenomenon.　For　the　spin　down　current,　the　bound　states　are　formed　as　the　magnetic　flux　takes　an　appropriate　value,　which　greatly　enhances　the　spin　polarization.　These　research　results　are　expected　to　contribute　to　the　design　of　future　quantum　function　devices.