We investigated the influence of a copper loading strategy over hexaaluminate on catalytic performance during the decomposition of an ammonium dinitramide (ADN)-based liquid propellant. Powder-type and pellet-type Cu/hexaaluminate catalysts were prepared and their chemico-physical properties were characterized by N2 adsorption, XRD, and XRF. A Cu-hexa-pellet-A catalyst in which copper atoms are positioned inside the hexaaluminate matrix showed the lowest decomposition onset temperature in decomposition of an ADN-based propellant. The excellent activity of the Cu-hexa-pellet-A catalyst is ascribed to copper being well incorporated in the hexaaluminate matrix, and the dispersion of the copper is higher than that in two other catalysts. When a thermal shock was applied at a high temperature of 1,200 °C prior to catalyst reuse, physical properties such as surface area, average pore diameter, and the compressive strength of the fresh catalyst did not deteriorate remarkably after five times repetitive reuse and heat treatment. Consequently, the Cu-hexa-pellet-A catalyst was confirmed to be a catalyst that has excellent activity and heat resistance simultaneously in decomposition of an ADN-based propellant.