Ectinib resistance is manifested by the deterioration of lung cancer in the course of treatment, such as the emergence of significantly enlarged lesions or metastasis. This drug is a first-generation targeted drug, and drug resistance is mainly manifested by the increase of lesions by more than 50% compared with that before treatment, or the emergence of new distant metastasis. If the original only pulmonary lymph node metastasis or mediastinal lymph node metastasis, now the new appearance of bone metastasis, brain metastasis, etc., are the manifestation of drug resistance. Almost all the current drugs, after patients use them for a long time, will produce drug resistance, and the cancer cells are no longer sensitive to the drugs, so that the effect of the drugs on the cancer cells decreases significantly. This leads to rapid recurrence of cancer, which is one of the main reasons for cancer treatment failure. As a targeted drug, after the emergence of drug resistance, patients need to carry out genetic testing to find the genes that are mutated again, and then modify the treatment plan for these genes that are mutated again, change the targeted drugs, or add chemotherapy or anti-tumor angiogenesis drugs on the basis of targeted drug treatment. The specific treatment plan should be in accordance with the doctor’s prescription.