Based　on　a　continuous　difference-in-difference　model,　this　study　evaluated　the　emissions　reduction　effect　and　regional　variation　and　the　mechanism　of　China＇s　carbon　trading　pilot　policies　from　2004　to　2017.　The　results　showed　that　the　carbon　trading　policy　could　reduce　the　carbon　intensity　of　the　pilot　areas　by　9.5%,　and　every　1%　increase　in　the　size　and　activity　of　the　carbon　market　brought　about　a　0.9%　and　0.7%　reduction　in　the　carbon　intensity　of　the　pilot　areas,　respectively.　In　terms　of　heterogeneous　impact,　the　carbon　trading　policy　had　a　significant　emission　reduction　effect　on　the　east　and　central　regions　while　it　had　no　significant　impact　on　the　western　areas.　Further,　the　carbon　trading　policy　had　a　significantly　higher　impact　on　carbon　reduction　in　developed　provinces　than　in　developing　provinces　in　China.　The　carbon　emission　reduction　effect　was　mainly　achieved　by　implementing　influence　on　the　enterprises　participating　in　the　market.　In　addition,　the　carbon　trading　policy　had　a　synergistic　pollution　reduction　effect,　reduced　sulfur　dioxide　emissions　by　22.7%　in　the　pilot　areas.　Therefore,　it　is　necessary　to　accelerate　the　national　carbon　market　and　increase　the　level　of　carbon　market　activity.　While　it　is　also　necessary　to　smooth　emission　reduction　channels,　and　promote　the　synergistic　emission　reduction　of　carbon　dioxide　and　other　pollutants.　©　2022,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.