In　the　research,　a　new　dechlorinating　agent　was　prepared,　using　the　activated　carbon　as　the　main　active　component　and　combining　the　other　cheap　raw　materials,　and　the　concerned　conditions　were　worked　out　during　the　production.　The　activated　carbon　derived　from　sewage　sludge　was　prepared　by　orthogonal　test.　Characteristics　of　the　activated　carbon　from　sewage　sludge　were　affected　by　3　factors　and　optimum　condition　was　obtained:　450　degrees　C　of　heating　temperature,　30　min　of　dwell　time　and　3　M　of　the　concentrations　of　ZnCl(2)　activation.　The　BET　surface　area　of　the　activated　carbon　under　optimum　conditions　is　299.57　m(2)/g　which　is　consistent　with　the　theoretical　result　of　orthogonal　design.　The　optimum　formula　of　the　new　dechlorinating　agent　after　the　researches:　30%　of　activated　carbon,　35%　natural　minerals　1　and　35%　industrial　waste　2.　And　the　dechlorinating　agent　has　a　breakthrough　chlorine　content　of　21.05%.　And　XRD　analysis　of　the　dechlorinating　agent　after　dechlorination　shows　that　CaCl(2)center　dot　4H(2)O　is　found　which　means　the　chemical　reaction　of　the　process.