The invention relates to an ointment used for treating dermatitis and a preparation method thereof, belonging to the technical field of traditional Chinese medicinal preparations. The ointment used for treating dermatitis mainly comprises active components like honeysuckle flower, bletilla striata, dahurian angelica root, Japanese snakegourd root, calamine, aloe, borneol, wild chrysanthemum flower, fructus forsythia, lightyellow sophora root, red sage root, white batryticated silkworm, largetrifoliolious bugbane rhizome, mulberry leaf, fructus tribuli, divaricate saposhnikovia root, periostracum cicadae, etc. and also comprises accessory materials. Through effective and reasonable combination, mutual cooperation and joint promotion of all the components, the obtained ointment specifically targeted at dermatitis has substantial drug effect, is applicable to a variety of dermatitis like infantile eczema, autosensitive eczema and infectious eczematoid dermatitis, has the advantages of good curative effect, short treatment course, fast action, strong effect, no irritation, safety and reliability, can fundamentally treat dermatitis, shows itching-relieving, acne-removing and spot-removing effect and exerts the effective effect of simultaneous treatment of principal and subordinate symptoms.