The so-called lung crusting does not have this term in clinical medicine, but specifically refers to the scarring of the lungs after trauma, at which time the scarring will have varying degrees of crusting, fibrosis, calcification and even other inflammatory reactions. Clinically, it is more common that the lungs are infected with viruses, bacteria and Mycobacterium tuberculosis due to trauma, causing inflammation in the lungs. After the inflammation is controlled or even cured by treatment, the lungs will heal to different degrees and form scar, which can be manifested as fibrosis, calcification, hyperplasia and granulomas of different degrees. Clinically, through the CT or MRI of both lungs, the scar after inflammation in the lungs can be found, which does not affect the normal work and life, without any obvious clinical manifestations, and does not need special treatment.