To identify ultra-high-performance liquid chromatography Q-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS), and to identify the diagnostic markers of RA and phenylpropanoid compounds associated with specific immune cell infiltration. RA(rheumatoid arthritis) gene chips were acquired through the GEO (gene expression omnibus) database, and consensus clustering was performed by the "consensus cluster plus" R package and distinguished into different molecular subtypes. Eigenes draw the ROC(receiveroperating characteristic curve) curve in the training and validation data set through R language software and calculate the area under the ROC curve. Immune cell infiltration results were entered through single sample gene set enrichment analysis. Correlation of phenylpropanoid compounds with signature genes based on SYBYL2.1.1 molecular docking analysis.4 Characteristic genes can affect 8 types of immune cells (activated CD4 + T cells, Central memory CD4 + T cells, Effector memory CD4 + T cells, The activated CD8 + T cells, monocyte, Regulatory T cells, Bone marrow-derived suppressor cells, Effector memory CD8 T + cells), and showed a positive correlation (P <0.05, P < 0.01, P < 0.001). Through UHPLC-QExactive/MS, 26 phenylpropanoid compounds can jointly intervene with four immune signature genes. The model based on immune cell infiltration can be used to predict the pathogenesis of RA, and the phenylpropanoid compounds have an intervention effect on immune signature genes, and Results provide a scientific basis for immunomodulatory therapy and early diagnosis of RA.