The main bearing in a low-speed marine diesel engine operates under varying loads and mixed lubrication conditions. The thin lubrication film of the bearing bush makes it susceptible to adhesive wear. A composite lubrication structure with graphene embedded into grooves was fabricated on the bearing bush using the UV-curing method. The tribological performance and release behavior of composite lubrication structures were studied. The composite lubrication structure shows the best tribological properties at a graphene-to-photoinitiator ratio of 3:7. Compared with the untextured and grooved surfaces, the wear loss of composite lubrication structure decreases by 41.9 % and 32.5 %, respectively. Graphene is gradually transferred to the contact interface to form a solid lubrication film, which improves the tribological performance of the main bearing. The release mechanisms include wear and extrusion, which are closely related to hardness, elastic modulus, compressive strength, and shear bond strength of filled materials. This study provides a reference for improving the tribological performance of main bearings in marine low-speed diesel engines.