This study aimed to explore the proteomic changes in twin pregnancies complicated with preeclampsia (PE) and identify potential biomarkers for early detection. Maternal plasma samples from twin pregnancies with PE (PE1, PE2, PE3) and healthy controls (CON1, CON2, CON3) were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The expression were further validated and investigated using cell-based assay. Differential proteins were identified, and bioinformatics analysis was performed to elucidate the involved pathways. Our results provide valuable insights into the molecular mechanisms of twin PE and potential biomarkers for clinical application.