The invention discloses a combined preparation and an application of the combined preparation in preparing a non-small-cell lung carcinoma drug. An EGFR (Epidermal Growth Factor Receptor) tyrosine kinase inhibitor and a preparation for increasing a concentration of glutathione (GSH) in lung carcinoma cells are administered simultaneously or successively. According to the combined preparation and the application, through a systemic research, the GSH plays an important role in resisting the EGFR tyrosine kinase inhibitor to an EGFR T790M mutation non-small-cell lung carcinoma, so that drug resisting cells are sensitive to treatment of the EGFR tyrosine kinase inhibitor again by utilizing a mode of increasing the concentration of the GSH in the lung carcinoma cells; and a cell experiment and an animal experiment prove that the method is safe and effective, can effectively kill the lung carcinoma cells, and can inhibit proliferation of the lung carcinoma cells.