Traditional Chinese medicine believes that the main causes of psoriasis are blood loss, wind blood dryness, wind-heat pathogen, and malnutrition of skin. Many physicians use the theory of traditional Chinese medicine to classify psoriasis, which is divided into blood deficiency type, blood stasis type and blood heat type. Psoriasis of blood heat type is equivalent to the progression of the disease, an important stage in the course of psoriasis. Improper treatment and drug abuse may lead to physical unbalance, and the condition may be temporarily relieved but easy to relapse, and may last for decades. Blood-heat type psoriasis is mainly manifested as skin lesions with bright color, and increasing and expanding of new skin lesions. With lesions exposed outside, patients often have physical and mental problems, resulting in reduction of work and life quality. External treatment of traditional Chinese medicine with a long history has unique advantages and experience, and it can penetrate skin pores, regulate channels and collaterals, and treat lesions directly. From the outside to the inside, treating both manifestation and root causes, this treatment can achieve obvious therapeutic effect.