In order to improve the resistance of tumor cells to chemotherapeutic drug, a method for sensitizing chemotherapy by promoting the cellular uptake of drugs has been developed. After cold atmospheric plasma treatment, reactive oxygen species in the medium increases significantly, further changing the permeability of cell membrane and allowing exogenous reactive oxygen species and calcium ions enter into cells. Meanwhile, changes in cell membrane permeability can increase cellular uptake of chemotherapeutic agents, and further increasing tumor cell killing efficiency. The results reveal that about 20% cells are killed with cold atmospheric plasma treatment. Doxorubicin as a regular anti-tumor drug shows 46% cell killing efficiency at the concentration of 4 μg/mL. After combined plasma treatment, the efficiency of cell killing is increased to 88% and the chemotherapy effect of doxorubicin is sensitized significantly. Moreover, cold atmospheric plasma combined gold nanorods presents 90% of cell killing efficiency, which is higher than gold nanorods alone (64%). In conclusion, cold atmospheric plasma can induce cell apoptosis and increase the uptake of chemotherapeutic drugs by changing cell membrane permeability, and sensitize the chemotherapy effect.