The　reduction　of　CO2　with　visible　light　is　a　highly　sustainable　method　for　producing　valuable　chemicals.　The　function-led　design　of　organic　conjugated　semiconductors　with　more　chemical　variety　than　that　of　inorganic　semiconductors　has　emerged　as　a　method　for　achieving　carbon　photofixation　chemistry.　Here,　we　report　the　molecular　engineering　of　triazine-based　conjugated　microporous　polymers　to　capture,　activate　and　reduce　CO2　to　CO　with　visible　light.　The　optical　band　gap　of　the　CMPs　is　engineered　by　varying　the　organic　electron-withdrawing　(benzothiadiazole)　and　electron-donating　units　(thiophene)　on　the　skeleton　of　the　triazine　rings　while　creating　organic　donor-acceptor　junctions　to　promote　the　charge　separation.　This　engineering　also　provides　control　of　the　texture,　surface　functionality　and　redox　potentials　of　CMPs　for　achieving　the　light-induced　conversion　of　CO2　to　CO　ambient　conditions.