Lip laser hair removal is directed by laser irradiation, which destroys melanin in hair follicles through photothermal effect. The principle is similar to photon hair removal. Hair growth cycle is used to completely depilate hair follicles after three minor injuries. Generally, in the process of lip laser hair removal surgery, there may be slight and instantaneous skin pain every time the laser is irradiated, and it will disappear after stopping the irradiation without anesthesia. After lip laser hair removal laser irradiation, the skin in the irradiated area appears temporary redness and swelling, and a "small swelling bag" appears at the pores, just like a small pimple after a mosquito bite, which can disappear naturally after 1-2 hours.