PCP is known as Pneumocystis carinii pneumonia, and on the one hand, it is a fungus mainly due to immunocompromised organisms, such as those infected in the case of HIV infection. On the other hand, PCP infections can also occur in normal people especially during the application of immunosuppressive drugs, or hormones. When the patient develops the above mentioned infections, acute exacerbation of the condition can occur, manifested as wheezing, chest tightness. Dyspnea, and in severe cases, more severe respiratory failure can occur, a condition that warrants prompt intervention to prevent acute respiratory failure due to infection. Commonly used drugs include sulfonamide, clindamycin, etc., of which compound sulfonamide drugs belong to the first-line drugs, with better anti-PCP effect, while strengthening the treatment of underlying diseases.