A　simple,　novel,　and　gram-scalable　fluorescent　probe　material　(NIT)　containing　a　2,2-diphenyl-1,3-dithiolane-bridged　bis-1,8-naphthalimide　unit　with　excellent　air　environment　stability　has　been　reported.　NIT　can　effectively　detect　Hg2+　according　to　the　variation　in　the　fluorescence　characteristics　of　NIT　with　and　without　Hg2+.　The　selectivity,　concentration　titration,　pH　applicable　range,　and　detection　limit　of　NIT　in　2-methyl　tetrahydrofuran/water　have　been　investigated.　The　results　show　NIT　possesses　high　selectivity,　a　wide　pH　applicable　range　of　3-13,　and　sensitivity　to　detect　Hg2+.　NIT　also　indicates　the　potential　application　in　real　environmental　water　samples　for　detecting　Hg2+.