Fast　linear　transformer　driver　(FLTD)　is　a　novel　high　pulsed　power　source　that　can　directly　drive　fast　Z-pinch　load,　radiography,　high　power　laser　and　high　power　microwave　etc.　Switch　is　one　of　the　most　important　components　which　affects　the　characteristic　of　LTD　module.　A　new　multigap　gas　switch　has　been　developed,　which　is　composed　of　six　equal　gaps　in　series.　The　total　gap　distance　is　30　mm.　In　the　switch,　every　intermediate　electrode　is　anchored　to　the　insulated　casing　by　three　bolts.　The　electric　field　distribution　of　the　switch　has　been　analyzed　for　designing　switch.　Experimental　results　show　that　the　curve　of　the　switch　self-breakdown　voltage　is　conformable　to　the　empirical　formula　,　and　the　divergence　of　the　switch　self-breakdown　voltage　is　less　than　3.2%.　When　the　ratio　charging　voltage　to　self-breakdown　voltage　is　50%,　the　switch　can　be　triggered　easily　and　the　delay　time　is　about　100　ns.　When　the　ratio　charging　voltage　to　self-breakdown　voltage　reaches　60%　and　the　trigger　pulse　is　150　kV/15　ns,　the　delay　time　reduces　to　60　ns,　and　the　jitter　time　is　less　than　5　ns.