Cream for treating psoriasis and its preparing process

This invention provides a cream for treating psoriasis and its preparation method. The cream is prepared by adding small dose of tretinoin into volatile oil of Rhizoma Zedoariae, packaging through modern pharmacy method, and making into oil in water compound cream with stearic acid, glyceryl monostearate, white vaseline, liquid paraffin, glycerol, triethanolamine, sodium lauryl sulfate, phenol ethyl ester, and distilled water. Compared with present technology, the inventive medicine has the advantages of high security, good therapeutic effect, no toxicity or adverse side effect, low recurrence rate, stable property, controllable quality, and low cost.