Grain-molded gun propellant was prepared based on nitramine propellant by surface-deterring, surface-coating, and grain-molding. Two ignition schemes including bottom configuration and central core igniter were designed. Results show that compared with the bottom configuration, ignition delay time shortens 15.2% and the maximum negative pressure difference decreases 8.41 MPa of central core igniter, and the maximum extrusion process of the propellant decreases 11.93 MPa, which indicate that central core igniter ignition scheme can bring perfect ignition performance for grain-molded gun propellant charge.