The　design,　fabrication　and　characterization　of　a　novel　electrothermal　actuator　for　MEMS　safety-and-arming　devices　are　presented　in　this　paper.　The　device　is　comprised　of　two　V-shape　electrothermal　actuators,　a　V-beam　amplification　and　a　mechanical　slider.　The　two　V-shape　electrothermal　actuators　generate　the　original　displacement　and　the　V-beam　amplification　is　used　to　amplify　this　displacement　for　arming.　The　characteristics　of　the　V-shape　actuator　and　V-beam　amplification　are　analyzed　and　validated　by　finite　element　method.　The　whole　device　is　fabricated　on　SOI　wafer,　and　MUMPs　process　is　introduced.　The　experiment　results　demonstrate　that　the　displacement　of　the　device　is　120.89　mu　m　with　consuming　power　of　3.12　W　and　response　time　of　16　ms　under　an　applied　voltage　of　16　V.　The　chip　size　is　about　4mm*5mm*0.5mm,　which　can　be　easily　integrated　with　other　micro　devices.