The formation of sun spots on the face is usually due to a large amount of UV exposure to the skin in a short period of time, which may stimulate the tyrosinase activity at the bottom of the skin and therefore secrete melanin to form sun spots. The causes of this situation mainly include inappropriate sun protection, too long exposure time or using poor quality cosmetics, etc. 1. Inappropriate sun protection: not paying attention to sun protection or inappropriate sun protection, failing to apply sunburn cream or wearing sun hat in time, etc., causing sun spots; 2. Too long exposure time: due to work, the skin receives a large amount of ultraviolet radiation in a short time or is exposed to the sun for a long time, which can lead to sun spots 3.Use of poor quality cosmetics: Some poor quality cosmetics contain excessive chemical metal components such as lead and mercury, or add irregular fragrances, which have the effect of absorbing light, thus leading to the formation of sun spots. It is recommended to choose suitable sunscreens according to the season when going out, avoid direct sunlight to the face, and avoid using cosmetics containing hormones, lead, mercury and other harmful substances. You can eat more fruits or vegetables containing vitamin C, and eat less or no photosensitive foods, such as leeks and carrots. If there are large sun spots, patients can also consult at the hospital and use laser to remove the spots.