A lot of small pimples on the face can be caused by acne, cornu rashes and flat warts. 1. Acne: Acne is caused by bacterial infection, inflammation, and increased sebaceous gland secretion, etc. The most common areas of this disease are the face, trunk, etc., and the clinical manifestations are pimples and pimples. 2. Corns: Corns can be caused by heredity, sweat duct damage, trauma and other factors, usually manifested as multiple yellowish-white hard pimples, preferably in the face. 3. Flat warts: the pathogenesis of this disease is mostly considered to be caused by HPV infection, sun exposure, trauma and immune system dysfunction and other factors may also trigger the disease. The patient’s skin will appear in different sizes, slightly elevated flat papules, the number is more, common in the face, the back of the hand, and so on. There are many diseases that cause a lot of small pimples on the face, and it is recommended that patients go to a regular hospital to clarify the cause of the disease.