Abstract： Objective： To observe the effect of expelling pathogen method of cooling the blood and resolving toxins （Yinxieling Prescription） on the recurrent symptoms of psoriasis vulgaris and the tissue-resident memory T cells（ TRM）. Methods：A total of 72 SPF male Balb/C mice，weighing about 18~22 g，were randomly divided into six groups， including the normal control group， the single-onset model group， the relapse model group， the positive medicine group （Methotrexate， 0.3 m·kg-1·d-1）， the low-dose Yinxieling Prescription group and the high-dose Yinxieling Prescription group （crude herbs，23.5 g·kg-1·d-1 and 47.0 g·kg-1·d-1），with 12 mice in each group. Except for the normal control group， the other mice were smeared with 50 mg of 5% Imiquimod Cream （IMQ） on the nude back，once a day for seven consecutive days. The mice given no any treatment were used as the models for psoriasis in remission stage. After four weeks，the second modeling was done （modeling for relapse）. Except for the normal control group and the single-onset mode group，the other mice were smeared with 50 mg of 5% IMQ on the back，once a day for five consecutive days. Administration：the administration was conducted respectively during the first modeling period and two weeks after modeling. The first psoriasis area and severity index（ PASI） scoring of skin lesions was performed in each group on the third day of the second modeling. The PASI scoring of skin lesions in each group was evaluated again on the fifth day of the second modeling； after the mice were sacrificed， their weight loss and spleen index were analyzed. HE staining was used to evaluate the pathological injury index of mucous membrane under the microscope； the expression of PCNA protein in skin lesions of mice was detected by immunohistochemistry；quantitative real-time PCR （qPCR） was used to detect the mRNA expression of psoriasis-related inflammatory factors； flow cytometry was used to detect the changes in the number of TRM cells in the lesion area，and qPCR was used to detect the expression levels of survival-related factors produced by TRM cells；immunohistochemistry and western blot were used to detect the phenotype of TRM cells and the expression of survival-related proteins. Results：Compared with the relapse model group，Yinxieling Prescription can alleviate the appearance symptoms of skin lesions in mice model of psoriasis relapse， inhibit the weight loss and epidermal thickening，and reduce the mRNA expression of interleukin （IL） 17，IL23，and tumor necrosis factor α（ TNF-α） and the expression of PCNA protein in the skin. Yinxieling Prescription can reduce the number of TRM cells with phenotype of CD3+TCRγδ+CD8+CD103+ in the skin lesions of psoriasis mice in the remission stage；it can also inhibit the mRNA expression levels of IL7，IL15，BCL6 and PRDM1 and the phosphorylation level of STAT5 in the skin lesions. Conclusion： Yinxieling Prescription can effectively alleviate the skin lesions of mice model of psoriasis relapse， whose mechanism may lie in the inhibition of the level of transcription factors formed by TRM， regulation of the STAT5 signal pathway of TRM survival and proliferation and the expression of downstream signal molecules （IL7 and IL15），reduction of the number of TRM cells in the primary skin lesion area in the remission stage so as to improve the recurrent symptoms of psoriasis.