Proteins exert their biological functions not only depending on abundance but also on regulation. Lactylation, a newly discovered post-translational modification, can mediate metabolic reprogramming and epigenetic regulation, and play a crucial role in signal transduction, gene expression, and cellular metabolism. Lactylation is involved in various diseases, such as tumors, Alzheimer’s disease, heart failure, and myocardial infarction, but there is little research in musculoskeletal system. In this study, we conducted lactylation modification omics on samples from rotator cuff tear and identified 2624 modification sites on 851 proteins. We obtained data on subcellular localization, histone sites, differentially modified proteins, functional pathway enrichment and proposed the concept of “lysine co-lactylation modification effect” through MOTIF sequence. Overall, after rotator cuff tears, lactate content significantly increases, lactylation widely occurs mainly located in cytoplasm, mitochondria, and nucleus and enriches in pathways such as RNA processing, DNA processing, and glucose metabolism. We hope that lactylation intervention can provide new ideas and therapies for the repair of rotator cuff tears.