Mycobacteria like warm, humid places, especially acidic environment, the most suitable for the growth of mycobacteria, its suitable pH is between 4.0-4.7, usually less than 4.5. Under normal circumstances mycobacteria is a conditional pathogenic bacteria, a very small number of women vagina will have this germ, but it will not develop, only after the human body’s resistance to decline will symptoms appear. The main clinical triggers for a woman’s reduced immunity are: 1) diabetes; 2) high doses of antibiotics and immunosuppressants; 3) pregnancy; and 4) high doses of estrogen therapy, all of which can easily lead to an attack of mycotic vaginitis.