"Fractional needle" is short for "femtosecond fractional laser", which is a kind of laser technology used for medical aesthetics. Femtosecond laser is the new trend of cosmetic lasers at present, and among the traditional laser cosmetic devices, the most satisfactory one should be "femtosecond fractional laser". Femtosecond fractional laser is a new type of laser technology, which utilizes the characteristics of ultra-short pulse and fractional scanning of femtosecond laser, which can produce tiny thermal damage on the surface of the skin and stimulate the skin's self-repairing mechanism, so as to achieve the effects of whitening, rejuvenating the skin and repairing the scars and so on. Meanwhile, due to the precision and safety of femtosecond fractional laser, it has become one of the current hotspots in the field of laser cosmetology.