With the progress of society and the development of technology, the life expectancy is increasing, but at the same time, the aging population is increasing, which also brings great pressure to the family, society and the country. The World Health Organization (WHO) defines people over 60 years old as the elderly, and defines society with more than 10% of the total population over 60 years old as an aging society. Since China entered the stage of aging population age structure in 1999, the speed of aging has gradually increased. The sixth census shows that the total population of mainland China has reached 1.339 billion, and the population aged 60 and above accounts for 13.26% of the total population of the country, which is one of the countries with the largest and fastest growing aging population in the world. The latest information shows that China’s elderly population is expected to exceed 200 million by 2013, and 10 million new elderly people will be added every year. It is expected that by 2033, the elderly population in China will exceed 400 million. Lung cancer has become the leading cause of death caused by cancer worldwide, and in China, the incidence of lung cancer is increasing and has become the number one cancer in China, and the incidence and mortality rate are growing most rapidly. Among them, about half of the lung cancer patients are over 60 years old, and most of them are men with smoking history. It is expected that by 2050, the number of lung cancer patients over 60 years old will be twice of the current number, therefore, lung cancer is also known as “senior cancer”. The clinical symptoms of lung cancer in the elderly are cough, chest pain, shortness of breath and coughing sputum, which are not specific and are also common symptoms of chronic obstructive pulmonary disease and tuberculosis, so it is easy for people to mistake these chronic diseases and not to seek timely medical treatment. On the other hand, more than half of the elderly lung cancer patients often have COPD or tuberculosis at the same time. The symptoms of these concomitant diseases often conceal the existence of lung cancer and weaken the vigilance of patients and medical personnel, thus leading to missed diagnosis. Some other elderly lung cancer patients have extra-pulmonary symptoms or manifestations due to metastases as their first symptoms, which make inexperienced medical personnel overlook the lung conditions, resulting in misdiagnosis or underdiagnosis. The above combined factors make the clinical misdiagnosis rate of lung cancer in the elderly as high as 5%-10%.