In　this　paper,　the　separation　of　tungsten　and　molybdenum　by　selective　precipitation　is　evaluated,　and　the　addition　of　cetyltrimethyl　ammonium　bromide　(CTAB),　as　complex　agent,　is　developed　to　reduce　Mo　loss.　Thermodynamic　equilibrium　calculations　show　that　manganese　salt　has　selectivity　to　precipitate　tungsten　from　molybdenum.　Through　single　factor　experiments,　the　influence　of　precipitation　factors　is　studied　systematically.　The　results　show　that　CTAB　can　enhance　the　separation　of　molybdenum　and　tungsten　by　manganese　salts.　Under　optimal　conditions　(temperature　50　degrees　C,　n(Mo)/n(CTAB)　=　2,　n(Mo)/n(W)　=　10,　time　1　h),　the　loss　rate　of　Mo　is　0.73%,　the　precipitation　rate　of　W　is　89.57%,　and　the　separation　factor　is　2411.67,　which　is　much　higher　than　the　separation　factor　of　molybdenum　and　tungsten　without　CTAB.　The　results　of　XRD　and　SEM　show　that　the　precipitates　mainly　consist　of　MnWO4　and　a　small　amount　of　MnMoO4　with　the　shape　of　the　flower　cluster　composed　of　flakes.　The　complex　effect　of　CTAB　is　verified　by　the　simulation　of　Cambridge　sequential　total　energy　package　(CASTEP).　The　results　of　geometric　optimization,　total　energy　and　density　of　states　together　with　FTIR　spectra　reveal　the　complex　mechanism　of　CTAB　with　MoO42-.　As　an　inexpensive　and　green　sorbent,　CTAB　can　be　used　to　enhance　the　effect　of　manganese　salt　precipitation　method　for　selective　separation　of　W　and　Mo　ions.