In order to explore the potential of pegylated black TiO2 mediated photodynamic therapy to inactivate HL60 cells, black pegylated TiO2?(PEG@B-TiO2) nanocomposites with different mass ratios were synthesized by the combination of hydrothermal reduction and surface modification method. The physicochemical properties of this prepared samples were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), ultraviolet and visible spectrum (UV-VIS), fluorescence spectra (FS), transmission electron microscopy (TEM), and granulometer, respectively. Then reactive oxygen species detection kit was used to detect the yield of reactive oxygen (ROS). In order to determine the drug which is most effective, cell proliferation experiment (CCK-8 method) was conducted to compare the toxity of different drugs on HL60 cells in darkroom condition and under visible light irradiation. The results indicated the prepared nanomaterials were with good dispersion, high crystallinity, low electron hole pair recombination rate and strong absorbability to visible light. At the same time, dark toxicity experiment suggested that the biocompatibility was good. Compared with pure TiO2, PEG@B-TiO2 showed higher inactivation efficiency under light irradiation, which manifested that they were expected to be an effective photosensitizer for treating leukemia by photodynamic therapy.