The invention relates to the field of oil and gas drilling, and concretely relates to a supramolecular material-containing additive composition for a water-based drilling fluid, the water-based drilling fluid, and applications of the additive composition and the water-based drilling fluid. The composition comprises a carrying agent and a filtrate reducer, and the carrying agent is a supramolecularmaterial formed by combining CaO, C, SiO2 and bound water; and the filtrate reducer is a crosslinked copolymer containing a structural unit provided by a monomer represented by formula (1), a structural unit provided by a monomer represented by formula (2), a structural unit provided by a monomer represented by formula (3) and a crosslinking structure provided by a crosslinking agent. The composition has good resistance to a high temperature and a high salt as a water-based drilling fluid additive; and the water-based drilling fluid containing the composition as an additive can maintain goodrheology, that is low viscosity, high shear force and strong shear dilution after being invaded with salt.