The side effects of having a picosecond are inflammatory reactions such as edema, pain and erythema of the affected tissues, and in severe cases, hyperpigmentation and depigmentation can be formed. The principle of picosecond laser is to use the strong energy of laser pulse to break the melanin tissue under the skin, and its operation will cause different degrees of damage to the skin. In addition to local inflammatory reaction, such as different degrees of pain, erythema, edema, can also form pigmentation, loss, if not properly operated easy to cause skin depression, or even the consequences of stiffness. Although picosecond laser has certain side effects, but the patient’s own physique is different, its reaction will be different, need to be different from person to person. It is suggested that patients should continue to do a good job of skin care and sun protection after the operation, which can avoid the occurrence of adverse reactions to a certain extent. If serious side effects occur after surgery, patients are advised to go to the hospital in time for standardized treatment under the guidance of the doctor.