Series　Z-scheme　NH2-UiO-66/PTCDA　(NU100PX)　composites　constructed　from　NH2-UiO-66　and　PTCDA　(3,4,9,10-perylenetetracarboxylic　dianhydride)　were　obtained　by　simple　ball-milling　method.　The　photocatalytic　Cr(VI)　reduction　activities　of　the　NU100PX　composites　were　conducted　upon　the　irradiation　of　low　power　LED　visible　light.　The　results　revealed　that　the　introduction　of　a　small　amount　of　PTCDA　on　the　surface　of　NH2-UiO-66　could　broaden　the　light　absorption　range　and　boost　the　separation　of　photo-induced　charge　carriers　to　promote　the　photocatalysis　efficiency.　The　influence　factors　toward　photocatalytic　Cr(VI)　cleanup　performances　of　NU100P10　like　pH,　initial　Cr(VI)　concentrations,　the　impacts　of　small　organic　acids　as　hole　capture　agents　along　with　various　co-existing　foreign　matters　were　clarified.　After　5　runs＇　adsorption-photoreduction　towards　Cr(VI),　the　NU100P10　still　exhibited　superior　reduction　activity　and　reusability.　The　Z-scheme　mechanism　of　photocatalytic　Cr(VI)　removal　over　NU100P10　was　put　forward　and　certificated　by　electrochemical　experiment,　ESR　(electron　spin　resonance)　test,　XPS　determination,　photo-deposition　and　DFT　(density　functional　theory)　calculation.