In　view　of　the　difference　from　LED　source　and　traditional　sources,　a　new　LED　lighting　simulation　system　based　on　DirectX　is　developed.　The　paper　has　investigated　the　advantages　of　developing　the　system　by　DirctX9　SDK,　and　combine　the　basic　theoietical　knowledge　of　computer　graphics　and　optics　to　research　the　principles　and　main　components　of　LED　simulation　system.　It　presents　a　LED　model　solution　and　a　human-computer　interactive　interface　design,　and　analyzes　the　simulating　results　of　this　system.