Abstract: Resin composition, resin adhesive film, and application thereof. The resin composition comprises the following components in parts by weight: 80-120 parts an epoxy resin, 1-20 parts a carbodiimide compound, 30-130 parts a phenolic resin, 20-250 parts a modified polymer, and 50-500 parts silicon dioxide; where the modified polymer is selected from a polyethersulfone or a polyamide-imide resin. By means of selection and compounding of components, the present resin composition has a uniquely advantageous film forming property, effectively solves the problem of a semi-cured resin adhesive film being prone to cracking or fracture, has outstanding heat resistance, a high glass transition temperature, a high modulus, good strength and toughness, and can to form a high strength stable bond with a metal film, has uniquely advantageous reliability, can amply satisfy printed circuit board and chip packaging performance requirements, and is suitable in a variety of chip packaging processes.