In recent years, malignant tumors have become important “killers” affecting human health worldwide, especially lung cancer, and the third survey of causes of death in the 21st century shows that lung cancer has become the leading cause of death from cancer. In addition, due to the highest prevalence of tobacco in the world and the impact of aging in China, lung cancer will remain a top priority for cancer prevention and treatment in China in the coming decades. At present, the incidence of lung cancer in China has been early, young, female, adenocarcinoma and diversified. In response to this trend, people should update the concept of prevention and treatment, get out of the misunderstanding and raise the awareness of early diagnosis and early treatment. In the prevention and treatment of lung cancer, early diagnosis is a very important aspect, and only with good early diagnosis can the next treatment plan be formulated based on the clinical information of patients. Early diagnosis and early treatment are important prerequisites for improving patients’ survival rate and good post-K. The statistical analysis of clinical records of Henan Chest Hospital shows that the early cases of lung cancer have slightly improved in the past two years compared with the previous ones. The reason may be related to two factors: one is related to the increase of local economic income level; the other is related to the improvement of people’s health awareness. Oncologists remind the public that in addition to the regular health checkups, they should do some relevant tumor screening under the guidance of oncologists according to their actual conditions. For example, thoracic surgery specialists may prompt the public to add chest CT examination and gastroscopy to detect early lung cancer, esophageal cancer and thymus tumor according to the patient’s condition. The diagnosis and treatment of malignant tumors can have a huge negative impact on the patients themselves as well as their families. Therefore, this reflects the importance of diagnosis from another aspect. With the continuous progress of medical research, people’s understanding of malignant tumors has become more in-depth and the classification has become more refined, and the treatment of malignant tumors has gradually become standardized. At present, academic circles at home and abroad have taken evidence-based medicine, diagnosis standardization and treatment individualization as the standard principles of malignant tumor treatment, and standardized and accurate diagnosis is an important prerequisite for standardized and fine treatment. Taking lung cancer as an example to make a brief explanation, lung shadow, literature data shows that about 81% of lung masses are malignant tumors. Therefore, when lung shadows appear, clinical doctors as well as patients should pay high attention to them. To explain, lung shadows include lung nodules and masses. Imaging will call those with a maximum diameter greater than 3 centimeters as masses and those less than 3 centimeters as nodules, and small nodules are divided into ground glass nodules as, partially solid nodules, and solid nodules. Data show that the chance of malignancy in lung masses is higher than that of nodules. When a ground glass nodule becomes partially solid or completely solid and/or increases in diameter, it means that the nodule is developing or has developed cancer. If the timing is right and a reasonable management plan is developed at this time, patients can often have a very good post-K outcome. For lung masses, chest CT is a non-invasive and important imaging test, but pathological examination is the “gold standard” for tumor diagnosis, so the diagnosis of lung cancer based on imaging alone is rather “crude” and not conducive to subsequent surgery, radiotherapy, chemotherapy and targeted therapy. It is also not conducive to the formulation of subsequent surgery, radiotherapy, chemotherapy and targeted therapy. In conclusion, lung cancer is a serious public health problem, and thoracic surgeons suggest that people should take preventive measures to reduce the occurrence of lung cancer.