Women’s body has to undergo a series of changes after pregnancy, such as hormonal changes in the body, lower body immunity and changes in the demand for nutrients, which can easily lead to changes in the oral environment and more diseases such as dental caries and gingivitis. Therefore, pregnant women should pay special attention to oral health care to prevent the development of oral diseases. (1) Adhere to the habit of brushing teeth every morning and evening and rinsing mouth after meals. Eat more food containing fiber. Insist on gum massage and proper use of oral health care tools such as toothpicks and dental floss. (2) The common oral diseases of pregnant women are dental caries, gingivitis, periodontal disease and pericoronitis of wisdom teeth, etc. Dental caries, especially during pregnancy when the body resistance is lowered, may develop rapidly and involve most or even all teeth with violent caries, which has great influence on the future life of pregnant women. Therefore, women should treat the caries that has appeared as early as possible before pregnancy. Gingivitis and periodontal disease are also easily produced and aggravated, leading to bleeding gums, loose teeth and pus overflowing from periodontium. The cause of periodontal disease should be removed as early as possible, such as removing calculus, plaque, periodontal medication, rinsing with 1:5000 chlorhexidine solution or brushing with suitable medicated toothpaste. The best way to prevent pericoronitis in “wisdom teeth” is to have the blocked third molar extracted before pregnancy to avoid recurrent episodes of pericoronitis during pregnancy that are difficult to control. (3) The nutrition of pregnant women is crucial, not only to the oral and general health of pregnant women, but also to the oral and general health of the fetus. For example, the lack of vitamin D, calcium, phosphorus and other minerals can affect the normal development of the fetal tooth structure, making the milk teeth prone to caries after eruption; it can also affect the fetal jaw development, resulting in malformation, so try not to be partial in pregnancy, to ensure the intake of protein, calcium, phosphorus and other minerals and various vitamins, to ensure the nutritional needs of the pregnant woman and the fetus, but also for the fetal oral and maxillofacial development and the prevention of oral and dental diseases. It also lays a good foundation for the fetal oral and maxillofacial development and the prevention of oral and dental diseases. (4) Prevention of infectious diseases during pregnancy is also very important, such as hepatitis, influenza and tuberculosis. These diseases may be transmitted to the fetus and affect the fetus’ maxillofacial development, so the oral health care of pregnant women cannot ignore the prevention of infectious diseases.