In the past, lung cancer patients usually choose traditional treatments such as surgery, radiotherapy and chemotherapy, which kill normal cells while removing tumor cells, and therefore bring a series of serious toxic side effects, and all of these treatments need to be done in hospitals, thus greatly reducing the quality of life of lung cancer patients. Therefore, the new idea of “targeted killing” or “targeted therapy” for malignant tumor tissues has emerged, which means that while killing tumor cells, normal cells are basically not damaged. This kind of drug acts on a certain part of tumor occurrence and development, such as inhibiting tumor blood vessel regeneration, inhibiting tumor cell proliferation, causing tumor apoptosis, inhibiting tumor cell invasion and metastasis, reducing tumor cell adhesion, and enhancing tumor cell sensitivity to chemotherapy drugs. Targeted therapy does not have the toxic side effects of traditional chemotherapeutic drugs, such as hair loss, severe vomiting, bone marrow suppression and other serious toxic side effects. At present, molecular targeted drugs, represented by ERSA and Tricor and so on, highlight their important position in the treatment of tumor patients, which can be used as a separate treatment in the treatment of non-small cell lung cancer, and applied in the first, second and third line treatment of lung cancer patients, due to their lower toxic side effects, once daily oral administration, good therapeutic effect and high quality of life without hospitalization, etc. Due to its advantages such as low toxic side effects, once-a-day oral administration, good therapeutic effect and high quality of life, and no need for hospitalization, it is becoming the most acceptable treatment for medical professionals and patients. The introduction of molecular targeted drugs has revolutionized the history of advanced non-small cell lung cancer treatment and brought new hope and gospel to lung cancer patients. In particular, it is worth mentioning that current molecularly targeted therapies are not effective for all NSCLC patients, so it is important to identify those patients who are most likely to benefit before starting treatment. Clinical populations of interest include Asians, women, adenocarcinoma and nonsmokers. Molecular biology testing for the presence of EGFR mutations is currently the gold standard for deciding whether to pursue first-line targeted therapy.