Aiming　at　the　problems　of　easy　agglomeration,　easy　oxidation　and　poor　removal　efficiency　when　2,4-dichlorophenol　was　removed　by　nano　zero-valent　iron　(nZVI)　alone,　a　kind　of　environmentally　friendly　material　of　carboxymethyl　starch　sodium　(CMS)　was　used　to　coat　nZVI　for　a　new　CMS-coated　Fe　0　preparation.　The　effects　of　single　factor　variables　such　as　coating　ratio　(CMS:　Fe　0　),　pH,　and　nZVI　dosage　on　the　removal　rate　were　investigated.　On　the　basis　of　single-factor　experiments,　the　response　surface　methodology　was　used　to　study　the　impact　of　multi-factor　interactions　on　2,4-dichlorophenol　removal　by　the　CMS　coated　nZVI　when　the　coating　ratio,　pH,　and　Fe　0　dosage　were　taken　as　the　investigation　factors,　and　the　removal　rate　of　2,4-dichlorophenol　(2,4-DCP)　was　used　as　the　response　value,　then　a　quadratic　polynomial　optimization　model　was　established　to　optimize　above　removal　process.　The　results　showed　that　the　optimal　conditions　are　following:　the　pH　was　3.0,　the　coating　ratio　for　nZVI　was　3.59:　1,　the　CMS　coated　nZVI　dosage　was　7.96　g·L　-1　The　maximum　removal　rate　of　2,4-DCP　predicted　by　the　model　was　90.03%,　and　the　corresponding　experimental　value　was　85.77%.　The　relative　error　of　4.73%　between　them　proved　the　reliability　of　the　optimization　model.　©　2018,　Science　Press.　All　right　reserved.