The side effects of hyperpigmentation are the same as those of other lasers, such as redness, swelling, blisters, hyperpigmentation, scarring and other side effects. Ultra-picosecond laser utilizes its selective photothermal effect to achieve the clinical purpose of removing spots, whitening and so on. Improper choice of energy or improper post-treatment care may cause skin damage, short-term redness and swelling will recover in 2-3 days; if the thermal burns are obvious, blisters appear, poor care, may leave pigmentation or even scarring. Ultra picosecond is a more advanced laser instrument, it is recommended that patients who have the will to treat choose regular hospitals, if there is abnormal skin damage, the energy should be adjusted down or directly interrupt the treatment, the use of growth factor gel, mupirocin and other topical prevention of infection. Wait for the skin to recover, choose other more suitable for the patient’s laser treatment instrument, and then do picosecond laser treatment.