A　new　nanocomposite　NaLuF4:　Gd,　Yb,　Tm-TiO2　photocatalyst　was　developed.　Its　morphology,　size,　crystalline　phase,　composition,　absorbance　and　emission　spectra　were　characterized　by　X-ray　diffraction,　transmission　electron　microscopy,　energy-dispersive　X-ray　analysis,　ultraviolet-visible　absorbance　and　fluorescence　spectroscopy.　The　photocatalytic　degradation　of　dyes　including　rhodamine　B　(RhB),　methyl　blue　(MB)　and　methyl　orange　(MO),　dye　mixtures　and　dye　wastewater　under　simulated　solar　light　irradiation　were　evaluated.　The　degradation　ratios　and　the　removal　ratios　of　chemical　oxygen　demand　(COD)　of　the　dyes　and　dye　wastewater　after　the　photo-degradation　were　measured.　The　results　show　that　the　as-prepared　nanocomposite　exhibits　high　photocatalytic　activity,　and　it　can　not　only　efficiently　degrade　single　dyes,　but　also　mixtures　and　dye　wastewater.