Cook-off test of GATo-3 propellant with different aging degree was carried out by a self-designed device. The self-ignition temperature and time to self-ignition of GATo-3 propellant under the different experimental conditions were experimentally obtained. The related kinetic parameters of GATo-3 propellant were obtained via calculation and the experimental phenomenon and law were analyzed. Results show that the self-ignition temperature of GATO-3 propellant is about 130 ℃, activation energy is 147.66 kJ·mol^-1 and pre-exponential factor is 2.72×10¹⁵ s^-1. The ignition temperature of the GATo-3 propellant at different environmental temperature mostly remains the same, but its time to self-ignition and intensity degree are different. The higher the temperature, the shorter the time to self-ignition and there is the more intense response degree. With increasing the storage time, the decrease of stabilizer content makes the decomposition rate accelerate, and the time to self-ignition short.