Patients who require lung transplantation have poor function on both sides of their lungs. A single-lung transplant involves removing one of the lungs and replacing it with a new lung, usually choosing the side with relatively poor lung function. However, in infectious end-stage lung disease, systemic immunosuppression after single-lung transplantation will lead to the spread of infection in the other autologous lung, which is often fatal, and therefore must receive a double-lung transplant, in which both infected lungs are removed and replaced with new lungs. Even in non-infectious disease, there are cases where a double lung transplant is safer, the post-operative management is relatively simple, and the results are better. Although the technique of double lung transplantation is more complex, with the development of technology, there is currently no significant difference in the success rate and cost of the procedure compared to single lung transplantation, while the improvement in long-term lung function and long-term survival rates are better than those of single lung transplantation. Therefore, double lung transplantation has almost replaced single lung transplantation in experienced lung transplantation centers abroad. Indications for double lung transplantation: 1. Suitable for all patients with single lung transplantation who are less than 60 years old (age limit can be relaxed appropriately according to the actual situation of the patient). For relatively young patients, double lung transplantation is a better choice. 2. End-stage infectious lung disease (e.g. cystic fibrosis, diffuse bronchial dilatation sign, etc.). 3, Severe obstructive lung disease with significant increased pulmonary artery pressure and right heart insufficiency. 4, When the donor quality is poor, double lung transplantation helps to safely survive the surgery. 5, Patients with non-infectious end-stage lung disease with a history of recurrent secondary infections, such as colonization with drug-resistant bacteria (e.g. Burkholderia cepacia, Pseudomonas aeruginosa, etc.) in the lungs, should undergo double lung transplantation. 6. Patients with primary pulmonary hypertension who receive single-lung transplantation have difficult perioperative management, high mortality and only limited improvement in postoperative quality of life; therefore, double-lung transplantation is a better choice.