Picosecond laser engraving machine is a kind of laser engraving equipment using picosecond laser technology. Its working principle is to crush pigment particles by ultra-short pulse laser, so as to achieve the effect of removing pigment. Picosecond laser engraving machine is mainly used to treat pigmented skin lesions, such as freckles and chloasma. Purple laser engraving machine is a kind of laser engraving equipment using ultraviolet light. Its working principle is to activate pigment particles by ultraviolet light to decompose them and be metabolized by human body. Purple laser engraving machine is mainly used to treat skin problems such as tattoos and pigmented spots.