The disadvantages of picosecond are as follows: 1, it will lead to swelling of the skin, the action principle of picosecond is to use the thermal effect of the laser to act on the epidermis layer of the skin, so as to smash the melanin particles, when the laser reaches the epidermis layer of the skin, it will stimulate the sensitive factor, resulting in the surface of the skin to become swelling. 2, it will lead to the skin to be more dry, when the use of picosecond to go to pigmentation of the skin at the same time the technology will speed up the division of the skin cells, facial Need a lot of nutrients and water, which will lead to the face more dry and tight. 3, picoseconds can also lead to inflammatory reactions, such as edema, redness and erythema, etc., but these drawbacks can be gradually recovered within a certain period of time by themselves.