Platelet-aggregation  receptor 1 (PEAR1) is a transmembrane receptor identified in 2005 and expressed mainly on platelets and endothelial cells. PEAR1 is a receptor protein that contacts platelets with each other and plays an important role in platelet activation and aggregation. Endothelial cells play an important role in maintaining vascular tone and vascular repair, and PEAR1 regulates the process of tumourigenesis and development by affecting their proliferation and associated neovascularisation. In recent years, PEAR1 has gradually been recognized as a potential target for anti-thrombotic drugs. This review focuses on elucidating the mechanisms of platelet endothelial aggregation receptor 1 and related signaling pathways in platelets and endothelial cells, and provides new ideas for the study of drug therapy for tumour-associated thrombosis.