Abstract In this work, blended composites with ultra‐high molecular weight polyethylene (UHMWPE) as matrix polymer, α‐zirconium phosphate (α‐ZrP) as filler, and sodium polyacrylate (PAANa) as compatibilizer were prepared. The interfacial interaction between PAANa as a compatibilizer and the components of α‐ZrP/UHMWPE was studied by molecular dynamics simulation. The friction and wear behavior of the GCr15 ball/composite friction pair under seawater lubrication under different loads were explored, and the friction and wear mechanism were analyzed. The results show that PAANa as a compatibilizer can effectively improve the interfacial interaction force between components of PAANa/α‐ZrP/UHMWPE composites. The composites exhibited different trends regarding the relationship between tribological properties and α‐ZrP content under various loads. The wear mechanism of composites under low load is mainly represented by extrusion deformation. With the increase of load, the wear mechanism of composites gradually changed into adhesive wear and abrasive wear (depending on the content of α‐ZrP). This work provides a theoretical basis for preparing and applying other α‐ZrP/polymer blend composites.