Picosecond after anti-black in about 3 to 6 months can disappear, the specific time can not be generalized, usually with personal daily care, physical and other factors. Picosecond that is, picosecond laser, through the laser pulse duration can reach picosecond level, so that the pigmentation in the selective photothermal effect, to promote the metabolism and absorption of pigment particles, the other more stimulate the generation of elastic fibers, collagen fibers, to improve skin texture, lighten the wrinkles, repair scars, commonly used to remove spots. After picosecond spot removal, pigment cell hyperfunction or improper care will all lead to anti-black. The recovery time of anti-black phenomenon after picosecond treatment takes about 3-6 months, which is affected by skin metabolism, skin condition and other factors. Scientific care can accelerate the improvement, such as: should pay attention to strict sunscreen, avoid excessive ultraviolet radiation; light diet, eat more food rich in vitamin C, vitamin E, etc.; to ensure adequate sleep and good mood, appropriate physical exercise; If after scientific care, a long time has not yet seen improvement, it is recommended that patients go to the regular medical institutions in a timely manner, if necessary, to comply with the guidance of specialists in the use of drugs, photoelectric treatment and other measures to improve the anti-darkness of the picosecond treatment.