Carboxymethyl chitosan (CMCS) is applied as a nanodelivery system carrier for sustained intracellular release of rose bengal (RB) and doxorubicin (DOX) to achieve combinational drug treatments. An integral analytical method was used to characterize the structure of CMCS-RB, the amount of RB and DOX, the average particle size, the zeta potential, and the morphology, including Fourier transform infrared (FTIR), nuclear magnetic resonance (1H NMR), ultraviolet visible spectroscopy (UV-Vis), scanning electron microscope (SEM), laser particle size analyzer and transmission electron microscopy (TEM). The results revealed that the maximum encapsulation efficiency and loading capacity of DOX into the CMCS-RB-DOX nanoparticles was 13.38% and 53.18%, respectively. The content of RB in the CMCS-RB prodrug was 11.25%. The release of RB and DOX under different conditions was investigated through dynamic dialysis. CCK-8 assay were used to study the inhibitory effect on normal cells and Cal-27 oral cancer cells. The cytotoxicity results of CMCS-RB-DOX nanoparticles showed excellent photosensitizer properties and strong efficacy of photodynamic therapy (PDT).