Hair microscopy is a very important adjunct to hair examination, which can greatly improve the accuracy of the diagnosis of hair diseases. Hair microscopy requires very solid clinical experience in hair diseases and long-term experience in the use of dermatoscopy, not having a hair microscope means that you can look at a hair microscope, and irregular examinations in barber stores, beauty salons, etc. cannot be trusted. It is recommended that hair loss patients must go to the dermatology department of a regular tertiary hospital to let an experienced dermatoscopist or hair specialist give you an examination in order to obtain accurate and useful examination results. In addition, the following matters should be noted before the examination to be able to better improve the results of the examination: 1, shampooing may make the changes under the hair microscope become inconspicuous or even disappear, therefore, the hair microscope examination should be preceded by at least 48-72 hours without washing your hair 2, no hair styling gel can be used. 3.If you do hair microscopy after haircut, you need to wash your hair first and then do it after 48-72 hours. 4.Can not use decorative hair fiber. 5.Light colored hairs such as blonde or gray hairs are not as good as black hairs when observed under the hair mirror. Therefore, for blonde or gray hair, it is recommended to perform hair microscopy after dyeing to dark hair color. It is best to perform a hair microscopy 7-14 days after dyeing and after washing 1-2 times to remove the leftover dye. 6. Patients with excessive scalp flaking should use keratinolytic products for 1-2 weeks after the first trichoscopic observation to remove excessive scales, and then perform the second trichoscopic examination to improve the visibility of scalp blood vessels.