Opportunistic infections caused by AIDS are pathogens that do not commonly cause infections in the human body, which can be contracted by AIDS patients due to the lowered immunity of the body. After invading the human body, HIV destroys the body’s immune cells, which leads to a decrease in the body’s immunity. Pneumocystis, Mycobacterium tuberculosis, Candida albicans, and other pathogens in the environment that do not often cause infections in healthy human beings are more likely to infect AIDS patients, and the infections that occur are called opportunistic infections. AIDS patients should pay attention to personal hygiene, avoid overwork, actively cooperate with the doctor’s treatment, reasonable diet to avoid secondary infection. At the same time, oral hygiene should be maintained and indoor ventilation should be maintained.