In general, a single picosecond can usually last 1-2 months. The picosecond laser refers to a laser with a picosecond pulse width, which is very short and has a strong ability to destroy pigments, and is currently used in clinical practice to treat pigmented diseases, such as light spots and facial whitening. The treatment effect is good, does not affect the skin, and the course of the disease is short, and no scars will remain after the treatment. The treatment of pigmented diseases with picosecond laser is usually set for 3-5 sessions, and each treatment usually lasts 1-2 months, depending on the type of pigmentation, and it is recommended to be given an individualized treatment plan by a professional doctor. In addition, after the picosecond laser treatment, patients are recommended to pay attention to skin care, avoid sun exposure, use sunshades or masks to block ultraviolet rays, pay attention to vitamin C supplementation and eat more fresh vegetables and fruits.