A co-crystal compound containing ammonium nitrate and benzo-18-crown-6-ether. Ammonium nitrate and benzo-18-crown-6-ether are used to form the co-crystal compound with hydrogen bonding in a mole ratio of 1:1. A melting point of the co-crystal compound falls within a range of 124˜130° C., and the co-crystal compound can be prepared by an evaporation method or an anti-solvent method. The co-crystal compound comes with a non-hygroscopic property, a low burning rate (7 MPa, 0.58 mm/s) and a high pressure index (n>0.6), which can be used for replacing the oxidizer of a common gas generator propellant.