The weather is getting warmer, beauty lovers have taken off their thick winter clothes and replaced them with colorful spring and even summer clothes. However, the excess body hair adds a lot of worries to many beauty lovers. Seeing that summer is coming, spring is a good time to remove hair. There are many methods of hair removal, the traditional methods are shaving, plucking, chemical hair removal and waxing hair removal, etc., the effect is temporary. Although electrolysis hair removal can permanently remove hair, but the cure rate is low, the side effects are large, easy to form scar, affect sweat gland secretion and so on. The new generation of cosmetic laser machine can effectively and permanently remove hair, its principle is the hair and hair follicle growth base hair matrix, in the hair growth period contains a large number of melanin, can selectively absorb the specific wavelength of laser, when the laser irradiation, the laser energy is selectively absorbed, precisely destroy the hair matrix without causing damage to the adjacent tissue, to achieve the purpose of permanent hair removal. Since human hair follicles are in different growth cycles, hair follicles in dormant phase will not be affected in laser treatment. Only when these hair follicles turn into the anagen phase and produce more melanin can the laser work, so several treatments are needed after each period to achieve long-term results. After 2 to 5 treatments, most patients can get permanent results, even if a small amount of regrowth, the regrowth of hair is thinner, shorter and lighter than the original, that is, the purpose of clinical treatment has been achieved. Generally speaking, the thicker and darker hairs (such as armpit hair and male beard, body hair, etc.) have good effect of laser treatment; while the finer and lighter or even white hairs have poor effect. In addition, the head and facial hair in the growth phase of the proportion of higher, so the number of treatments required less, while the limbs, bikini hair required a slightly higher number of treatments; head and facial hair also due to the short growth cycle, so the treatment interval is only about 1 month. On the contrary, the hair on the limbs and perineum require a slightly longer interval. There are also studies that show that the histological structure of the sweat glands is not destroyed after laser hair removal, and the function of the sweat glands is basically unaffected by clinical observation of patients. Laser hair removal has almost no side effects.