Objective To investigate the expression and regulatory mechanism of PTPN2 in psoriasis, and to analyze the effects of PTPN2 on psoriasis related immunity in order to determine whether PTPN2 can be used as a potential therapeutic target for psoriasis. Methods R language (3.6.3 version) was used to determine the difference in expression levels of PTPN2 between psoriatic patients and controls, and the receiver operating characteristic (ROC) curve of PTPN2. The Gene Enrichment Analysis software (GSEA) and the Protein Interaction Analysis Database (STRING) were used to determine enrichment pathway of PTPN2 in the psoriasis dataset, and the interaction network of PTPN2 co-expressed genes. The distribution and expression of immune cells in psoriasis datasets were analyzed with CIBERSORT software. The differential expression of immune response pathways and immune response gene sets in psoriasis and their correlation with PTPN2 were analyzed using R language (version 3.6.3). Results PTPN2 mRNA was highly expressed in psoriatic lesions. Immune infiltrating cells, immune response pathways, and immune response gene sets were abnormal in psoriatic lesions. PTPN2 was associated with some immune infiltrating cells, immune response pathways, and immune response gene sets in psoriasis. Conclusions PTPN2 mRNA is highly expressed in psoriatic lesions, and may participate in the occurrence and development of psoriasis by regulating the immune microenvironment.