The　development　of　infrared　photodetectors　is　increasingly　moving　towards　the　realization　of　large-scale,　cost-effective　integrated　systems.　Currently,　silicon　(Si),　indium　gallium　arsenide　(InGaAs),　and　mercury　cadmium　telluride　(HgCdTe)　dominate　infrared　photodetectors,　but　due　to　the　ever-increasing　performance　requirements　and　the　complexity　of　emerging　application　scenarios,　a　new　generation　of　detector　technologies　is　imperative.　Colloidal　quantum　dots　(CQDs),　which　are　compatible　with　existing　silicon-based　microelectronics,　with　low　manufacturing　costs　and　simplified　processing,　are　ideal　alternatives.　Hg-　or　Pb-based　infrared　photodetectors　have　been　widely　studied　owing　to　their　excellent　performance.　Nevertheless,　the　presence　of　heavy　metal　elements　greatly　limits　the　application　scenarios　of　the　detectors.　Therefore,　heavy　metal-free　(HMF)　CQD-based　infrared　photodetectors　solve　the　above　problem　from　the　source.　In　this　work,　the　latest　advancements　in　the　synthesis　of　HMF　CQDs　and　a　brief　overview　of　the　development　of　HMF　CQD-based　infrared　photodetectors　are　given.　Within　the　context　of　this　field,　we　summarize　the　possible　forward-looking　directions　and　obstacles.　Heavy　metal-free　colloidal　quantum　dots　(CQDs)　are　ideal　materials　for　overcoming　heavy　metal　problems.　In　this　paper,　the　synthesis　progress　of　CQDs　and　their　phased　research　progress　in　the　field　of　multi-type　infrared　detection　are　reviewed.