Abstract: Thermal decomposition behavior of pure single base spherical powder(NC), glycidyl azide polymer (GAP) and GAP modified single base spherical powder were investigated by means of TG-DTG and DSC test methods. The interaction among main ingredients NC and GAP were discussed. The experimental results show that the thermal decomposition process of GAP exists in the thermal decomposition process of the mass fraction of 20% or 30% GAP modified single base spherical powder and, compared to the corresponding peak temperature of pure GAP, the thermal decomposition peak temperature of main chain is 3.5℃ and 8.4℃ in advance, respectively. DSC tests show that the decomposition exothermic peak of —N₃ group of the mass fraction of 20% and 30% GAP modified single base spherical powder is respectively reduced by 8.18℃ and 7.70℃ by the thermal decomposition products and heat of NC. It indicates that the presence of NC could promote the thermal decomposition of GAP modified single base spherical powder.