Infections are always an important part of complications in patients after hematopoietic stem cell transplantation, and pulmonary infections are the most common among infections. The following methods are used to deal with pulmonary infections after HSCT: 1. Search for the pathogens of pulmonary infections. This includes sputum culture; alveolar lavage, using the lavage fluid to find the pathogen; in the lavage fluid can also be sequenced to find the pathogen; 2, anti-infection treatment, anti-infection treatment is mainly based on different pathogens to choose different anti-infection drugs; 3, improve the patient’s immunity, you can use gammaglobulin to improve the patient’s immunity.