In　this　work,　a　novel　snap-through　mechanism　of　a　thin　beam　confined　in　a　curved　constraint　and　driven　by　local　loading　curvature　is　investigated.　The　movable　boundaries　of　the　buckled　thin　beam　enable　it　to　output　snapthrough　rotation　at　a　lower　energy　input　than　the　double-clamped　beam　structure.　A　theory　is　proposed　to　reveal　the　snap-through　mechanism　of　the　proposed　structure　based　on　the　principle　of　minimum　potential　energy　and　saddle-node　bifurcation,　which　uncovers　the　influences　of　loading　positions,　length　ratio　and　constraint　radius　on　the　critical　loading.　Both　theoretical　and　experimental　results　show　that　the　large　loading　position　and　small　constraint　radius　correspond　to　a　large　critical　loading,　while　the　length　ratio　hardly　affects　the　critical　loading.　In　addition,　an　experimental　device　is　designed　to　output　linear　displacement　based　on　the　proposed　snap-through　mechanism.　Due　to　lower　energy　input　and　snap-through　response　characteristics,　the　proposed　bistable　mechanism　exhibits　great　prospects　in　energy　harvesters,　actuators,　motors,　pumps　and　robots.