Hair transplantation surgery is a new and rapidly developing international technique for the treatment of permanent hair loss. It involves the surgical redistribution of some of the hairs from the residual scalp dominant donor area to the scalp hair loss area or other hair loss areas of the body. The so-called scalp hair dominant donor area is the area where normal hair remains for life and is available for transplant application. It is usually within 6-8 cm of the occipito-temporal area into the hairline. These transplanted hairs, after a short recovery from surgical trauma, maintain all their original growth characteristics and continue to grow in the new transplanted area. And they exist for life. Hair transplantation surgery, like other cosmetic surgery, is rapidly growing around the world due to popular demand. In Western societies, surgical treatment of hair loss has become the most common procedure in male cosmetic surgery. It has been reported that about 25% of men aged 25-30, 40% of men aged 40, and 50% of men aged 50 exhibit varying degrees of hair loss, and about 20% of women are also affected by hair loss to varying degrees, making hair transplantation surgery in great potential demand. Among the many factors of hair loss, the most common hair loss condition is androgenetic alopecia (typical hair loss in men or women), commonly known as “alopecia areata”, which accounts for about 95% of cases. Although the pathogenesis of this condition is not well understood, scientific studies suggest that it is mainly caused by genetic predisposition and relatively high levels of androgens in the body. Testosterone, a representative of androgens, is metabolically degraded by the enzyme 5-catabolism to 5-dihydroxytestosterone (DHT). It is currently believed that DHT stimulates androgenic-genetic hair loss. The possible process is that the genetically predisposed susceptible hair follicle cells are exposed to high levels of DHT for a long period of time, resulting in progressive hair loss. Although a proportion of patients are accompanied by increased cutaneous seborrhea, scientific data show no significant causal relationship between seborrhea and the development of the disease. In addition, neither ischemia nor hypoxia of the head nor stressful states are major factors in the development of this disorder. Although there are numerous treatments available for this type of condition, each of which is claimed to have varying degrees of efficacy, hair transplant surgery remains the only lasting solution to this problem. Other secondary factors include infections and trauma (e.g. burns), autoimmune diseases (baldness, commonly known as “ghost shaving”), severe trauma, malnutrition, anemia, endocrine disorders, and special medical treatments can also cause hair loss. The main targets of hair transplantation surgery are androgenetic alopecia and permanent scarring alopecia caused by trauma and infection. Surgical procedures include free hair transplantation, hair loss area reduction, scalp flap transfer and scalp tissue expansion. The choice of method depends on the patient’s condition and can be a combination of several methods. Free hair transplantation (commonly known as hair transplantation) is the most popular surgical treatment due to the low risk of surgery, low pain and natural results after surgery. Hair transplant units of various sizes are obtained and prepared for implantation in the area of hair loss or the area to be transplanted. In addition to treating permanent hair loss on the scalp, this technique also allows for the reconstruction of eyebrows, eyelashes, male beard and pubic hair as well as the cosmetic reconstruction of the hairline. It can relieve the physical and mental suffering of patients with permanent body hair loss. Since this hair transplantation procedure redistributes hair from the remaining dominant donor area, the procedure is only suitable for patients with sufficient hair donor area. The survival rate and results of hair transplantation are directly related to the operator’s delicacy and technique. Rough techniques not only fail to achieve the treatment goal, but also waste the very precious permanent hair remnant donor area. Often, patients can be deprived of the opportunity for reoperation. This should be of great concern to all patients and practitioners.