If the ear is suddenly swollen underneath, it is more likely to be a local soft tissue contusion, especially after trauma, and there will be obvious swelling, congestion and tenderness, and local ice can be given in the acute stage. In addition, if skin diseases occur, sebaceous cysts can easily develop secondary infections and even form abscesses, so the patient will have obvious local swelling, pain, fever, increased skin temperature on examination, and even a sense of fluctuation will be palpable. If necessary, surgery should be further selected for incision and drainage. After surgery, it is also necessary to cooperate with anti-infection treatment and intermittent medication changes, while during the treatment and recovery period, attention should also be paid to stay away from smoking and drinking environment to avoid affecting wound healing, pay attention to rest and work strenuous.