In　terahertz　(THz)　quasi-optical　systems,　the　real-time　profiling　and　visualization　of　THz　beams　is　of　great　importance　for　beam　focusing　and　collimation　applications.　Herein,　a　cost-effective　and　room-temperature-operated　THz　imaging　device　for　this　purpose　is　demonstrated　experimentally　using　a　flexible　and　broadband　THz　absorber　based　on　a　vertically　aligned　carbon　nanotube　(VACNT)　array.　Excellent　THz　absorption　performances　with　an　average　power　absorptance　＞96.8%　are　achieved　within　0.1　and　2.5 THz.　The　energy　of　the　incident　THz　wave　is　absorbed　by　the　THz　absorber　and　converted　into　heat　that　will　re-radiate　and　can　be　detected　by　an　infrared　(IR)　camera　as　a　result　of　the　THz-to-IR　conversion　mechanism.　Real-time　THz　beam　imaging　and　monitoring　applications　are　demonstrated　by　a　series　of　experiments　at　both　0.1　and　0.3 THz,　providing　an　alternative　approach　for　real-time　beam　profiling　and　monitoring　of　THz　waves.　©　2022　Wiley-VCH　GmbH.