Objective To evaluate the clinical efficacy of the diagnostic and treatment project of blood-heat syndrome in psoriasis vulgaris based on the results by Set Pair analysis. Methods A total of 180 patients with psoriasis vulgaris were randomly divided into 3 groups. 60 patients in the traditional scheme group were treated with modified Xijiao Dihuang Decoction（ 犀角地黄汤）

one dose per day; 60 patients in the set pair analysis group were treated with the result of set pair analysis method

one dose per day; 60 patients in the western medicine group were treated with Abamectin A

30 mg each time

once a day for oral administration. The 3 groups were treated for 4 weeks. The psoriasis lesion area and psoriasis area and severity index（ PASI） before and after treatment were observed

and the curative effects were determined after treatment. Results The total effective rate was 88. 14% and the obviously effective rate was 61. 02% in the set pair analysis group. The total effective rate was 82. 75% and the obviously effective rate was 50. 00% in the traditional scheme group. The total effective rate of western medicine group was 67. 24%

and the obviously effective rate was 17. 24%. The set pair analysis group was similar to the traditional scheme group

and there was no significant difference between the 2 groups（ P > 0. 05）

but both groups were superior to the western medicine group（ P < 0. 05）. Set pair analysis group was better than traditional scheme group and western medicine group in reducing PASI scores（ P < 0. 01）. There were 13 cases of gastrointestinal discomfort in the western medicine group

8 cases in the traditional scheme group

6 cases in the set pair analysis group

which did not affect daily life. Conclusion The treatment scheme based on set pair analysis is a safe and effective method for the treatment of psoriasis vulgaris with blood-heat syndrome

which can significantly improve the PASI scores of patients.