The area of 1000 hair follicles for hair transplant is around 10~20 square centimeters. Under normal circumstances, there are about 80~140 hair follicles per square centimeter of hair growth, but the density of hair transplantation in hair transplantation surgery is lower than that of normal growth, about 50~100 follicles per square centimeter, which needs to be decided according to the thickness of the patient’s hair, as well as combining with the patient’s wishes. If the original hair density is relatively low, the number of follicular units to be planted is usually relatively large. Generally, if the patient’s own hair thinning is mild, the area of 1,000 hair follicles to be transplanted is about 20 square centimeters; if the patient’s own hair thinning is more serious, the area of 1,000 hair follicles to be transplanted is about 10 square centimeters. Before hair transplantation, avoid the use of aspirin and other anticoagulant drugs and traditional Chinese medicine, tonic and other blood-activating drugs, avoid smoking, drinking alcohol, female patients need to avoid menstruation; hair transplantation need to pay attention to the local do not get wet within 3 days to prevent infection, avoid stimulating food within 7 days, after the operation need to comply with the doctor’s instructions to the outpatient clinic to observe the change of medication, and at the same time, need to monitor closely the implantation area, once redness, swelling and other discomforts, go to the hospital in time to seek medical attention.