Disclosed is a pharmaceutical composition for treating skin diseases which comprises the following components (by weight ratio): ginseng 20-40 parts, astragalus root 30-80 parts, capsule of weeping forsythia 5-20 parts, ledebouriella root 10-40 parts, notopterygium root 5-30 parts, levisticum 5-50 parts, flavescent sophora root 10-50 parts, phellodendron bark 5-20 parts, broom cypress fruit 10-30parts, cnidium fruit 10-30 parts, centipede, cassia seed 5-20 parts, hornet nest 10-30 parts, licorice root 5-30 parts, herba schizonepetae 5-20 parts, peppermint 5-20 parts, antelope's horn 10-80 parts, cocklebur fruit 10-50 parts, black-tail snake 10-80 parts, dried human placemta 10-30 parts, agkistrodon acutus 10-50 parts, coralbean bark 5-30 parts, secretio bufonis 10-30 parts, ophicalcite 10-50 parts, lead monoxide 10-50 parts, large-leaf gentian root 10-80 parts, and musk 5-20 parts.