The present disclosure relates to the field of display, in particular to a composition for an overcoat layer, a preparation method for the same, an overcoat layer material, and a display substrate and a display device including the overcoat layer material. The composition for the overcoat layer comprises: 10 to 30% by weight of styrene, 10 to 30% by weight of an epoxy resin, 1 to 3% by weight of a crosslinking agent, 0.1 to 0.5% by weight of a photoinitiator and/or a thermal initiator, 1 to 3% by weight of a surfactant, and 40 to 77% by weight of a solvent. The composition for the overcoat layer has styrene as a main monomer component, and may be initiated to cure by an initiator to obtain the overcoat layer material.