HIV primarily attacks the body’s immune system, which destroys immune cells and causes a decline in its own immune function, leading to a variety of opportunistic infections and tumors. The most common cause of death from AIDS is opportunistic infections, most commonly Pneumocystis pneumonia. For general patients, the main manifestations of Pneumocystis pneumonia are fever, cough, chest tightness, etc. The symptoms of chest tightness are usually not obvious at first, but they will progressively worsen and even respiratory failure may occur. For Pneumocystis pneumonia, the current preferred treatment option is SMZ, and if the disease is very severe, additional drugs of the echinocandin class are required. In patients with Pneumocystis pneumonia, the treatment can be life-threatening if left untreated.