Lung cancer has become the first cause of death from malignant tumors, and its incidence and mortality rates are increasing year by year. It is expected that by 2025, China will have 1 million lung cancer patients, making it the world’s number one lung cancer country. Lung cancer treatment includes surgery, chemotherapy, radiotherapy, traditional Chinese medicine, immunotherapy and targeted therapy, which has emerged in recent years. Targeted therapy has the advantage of killing tumor cells with high selectivity without killing or rarely damaging normal cells because of its clear therapeutic target. It is regarded as the first line of hope by many lung cancer patients. With the development of clinical application of targeted drugs, it has indeed brought new hope to more and more patients with advanced lung cancer. The myths about the efficacy of targeted drugs are also becoming more and more miraculous in the society, and the phenomenon of blind use of targeted drugs has emerged. So, what kind of patients are suitable for targeted therapy? Targeted therapy, as the name suggests, is a treatment method with the target as the guiding direction, so only patients with the target can choose targeted therapy, and only patients with the target can benefit from the targeted therapy. The so-called target is also the state of gene mutation. In the pathogenesis of lung cancer, many different gene mutation conditions have been identified, and some drugs targeting gene mutations have been invented and applied in the clinic. One of the most common genetic mutations is the human epidermal growth factor receptor (EGFR) gene mutation, and these patients then have the option of epidermal growth factor receptor tyrosine kinase inhibitors as targeted therapy, with specific drugs including erlotinib (Troche), gefitinib (ERSA), erlotinib (Kemena), and afatinib. These drugs are designed to control tumors by blocking the signaling pathways through which tumors occur. It has a fast onset of action and relatively few adverse effects, making it the best choice for lung cancer patients who have lost the chance of surgery, or who have relapsed after surgery and have more advanced disease. If resistance to such drugs occurs, which is tested to be caused by a clear drug resistance gene, then treatment targeting the resistance gene can be chosen again. Besides, lung cancer patients may also have K-ras mutation of proto-oncogene, EML4-ALK gene recombination, BRAF gene mutation, c-MET gene amplification, etc., all of which can be selected as different drugs for targeted therapy. Therefore, when making lung cancer diagnosis, besides clarifying the histological pathological type, genetic testing must be done to understand the genetic status and find out the targets in order to better guide the clinical selection of individualized treatment plan, so that patients can receive more reasonable, scientific and effective treatment.