A　new　structure　of　transverse　micro-stack　semiconductor　laser　bars　is　put　forward　to　improve　the　output　optical　power　of　semiconductor　laser　bars　at　low　injection　current,　which　can　effectively　lessen　the　thermal　damage　and　catastrophic　optical　damage　(COD).　Micro-stack　tunnel　regeneration　tri-active　regions　laser　diode　bars　are　fabricated.　Experiments　show　that　the　output　optical　power　is　79.3　W　and　slope　efficiency　exceeds　1.81　W/A　under　50　A　driving　current,　which　is　two　times　of　that　of　the　traditional　single-active　bars.