Electroactive　asymmetric　bis-carbazole　small　molecules　bearing　cyano　functional　group(s)　were　conveniently　synthesized　and　fully　characterized　by　physicochemical　and　electrochemical　methods.　These　carbazole-based　small　molecules　are　colorless　in　the　neutral　states　and　possess　reversible　redox　processes　and　outstanding　thermal　stability.　The　utilization　of　these　bis-carbazole　small　molecules　as　the　electrochromic　materials　for　the　fabrication　of　electrochromic　devices　(ECDs)　provided　high-performance　ECDs　of　high　optical　contrast　up　to　99%　switching　between　colorless　bleaching　state　and　dark-red　colored　state　and　excellent　coloration　efficiencies　of　412　cm2/C.　The　present　work　illuminates　the　excellent　qualification　of　functionalized　carbazole-based　small　molecules　in　developing　efficient　ECDs.