High　beam　quality　pulsed　Q-switched　Nd:YAG　solid-state　laser　450m/s　high　speed　online　laser　drilling　and　marking　system　is　reported.　By　PCL-836(A)　realizing　the　control　of　laser　power　supply,　AQ-switcher　and　two-dimension　scanner.　Synchronizing　pulsed　laser　and　AQ-switcher　through　the　delay　of　industry　computer,　and　realizing　short　pulsed　width　for　laser　drilling,　long　pulsed　width　for　laser　marking　through　setting　the　releasing　time　of　laser　power　supply.　And　adopting　the　two-dimension　scanner　to　catch　up　with　the　high　speed　moving　thin　steel,　which　keeps　the　laser　and　steel　relatively　inaction.　Drill　at　different　positions　of　the　moving　steel,　and　use　the　pinhole　to　test　the　drilled　holes.