A mole on the scalp of a child is a bit big, clinically it is usually considered as a pigmented mole, which has little effect on the body and can be treated accordingly if it affects the aesthetics. Pigmented nevus may be some kind of misshapen tumor or benign proliferation of melanocytes, the cause of most nevi is not clear, clinically considered to be related to congenital heredity, developmental defects, external environmental stimuli and other factors. Congenital nevus is usually associated with gene mutation during embryonic development, and acquired nevus is usually associated with ultraviolet irradiation in the environment, trauma, and side effects of drugs. Nevus pigmentosus usually occurs on the head and face, and the examination can find skin lesions on the surface of the skin as well as changes in the color of the skin lesions, and in some cases, it may be accompanied by pimples, plaques, etc., but it does not have any uncomfortable effects on the body. If it affects the appearance, parents are advised to take their children to the hospital dermatology department for diagnosis and treatment, and hormone surgery to remove the treatment after a clear diagnosis. Children have a mole on the scalp is a little big, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, to give targeted treatment or treatment.