After doing photorejuvenation face darkening can be treated by medication, picosecond laser treatment and other ways. Usually, the face becomes black after photorejuvenation treatment, it is possible that the melanin cells of the facial skin will be damaged, and these dead cells will gradually rise to the surface layer of the skin, which visually looks darker; or after photorejuvenation, do not pay attention to sunscreen to appear hyperpigmentation, resulting in the face becomes black. 1. Medication:You can apply or take some antioxidant treatment, such as vitamin C, vitamin E, etc., which can play the role of antioxidant, reduce melanin deposition and improve facial color. Hydroquinone cream can also be used externally to promote pigment absorption and metabolism of drugs. 2. Picosecond laser: Picosecond laser can reach deep into the skin through the photothermal effect of the laser and break the melanin particles in the surface and deep layers of the skin, so as to improve the color of the face and make the skin more delicate and fairer. It is recommended that patients go to the dermatology department of regular hospitals for consultation and reasonable treatment under the guidance of specialists, and not blindly self-medication. Normally, it is necessary to strictly sunscreen, avoiding direct exposure to ultraviolet rays.