Updated project metadata. Background Systemic lupus erythematosus (SLE) is a severe systemic autoimmune disease with multiple manifestations. Lysine crotonylation (Kcr) is a newly discovered post-translational modification (PTM) epigenetic pattern which may affect gene expression and linked to diseases causally. Methods We collected blood samples from 11 SLE individuals and 36 healthy subjects. Then we used highly sensitive liquid chromatography-mass spectrometry technology to carry out proteomics and quantitative crotonylome analysis of SLE peripheral blood mononuclear cells in this investigation, which indicated the unique etiology of SLE. Results There were 618 differentially expressed proteins (DEPs), and 612 crotonylated lysine sites for 272 differentially modified proteins (DMPs) found. According to KEGG analysis and ingenuity pathway analysis, these DEPs and DMPs are primarily enriched in the leukocyte extravasation signaling pathway. Conclusions This is the first study of crotonylated modification proteomics in SLE. The leukocyte extravasation signaling pathway had a considerable concentration of DEPs and DMPs, indicating that this pathway may be involved in the pathogenic development of SLE.