Dental cancer is caused by long-term smoking, chronic stimulation and injury, poor oral hygiene and so on. 1. Long-term smoking: smoking is an important factor in the development of gum cancer, because tobacco contains more toxic ingredients, and long-term smoking forms stimulation to gums, which may cause dental cancer. 2. Chronic stimulation and injury: for example, misalignment of teeth, cheek biting habit, residual roots and crowns formed after uneven wear and tear of teeth, pointed tooth tips, dental calculus and so on, all of them may puncture the oral mucosa, and long-term stimulation may develop into gum cancer in general. 3. Poor oral hygiene: poor oral hygiene can easily lead to bacterial growth and increase the formation of chemical carcinogens such as nitrosamines. The prevention of oral cancer lies in reducing external stimulating factors and actively treating precancerous lesions. It is suggested that dental cancer patients should go to regular hospitals as early as possible for early treatment under the guidance of doctors.