The energy performances of glycidyl azide polymer (GAP)/ nitrocellulose(NC) cross-linked modified double-base propellant, in which GAP modified nitrocellulose powders was used as binder, were calculated by a propellant energy characteristic calculation program. The smoke signature of the propellant was evaluated by the content of Al₂O₃ and HCl in combustion products. Results show that with increasing the content of plasticizer glycidyl azide polymer azide (GAPA), the theory specific impulse increases first and then decreases. With increasing the content of GAP in binder, the theory specific impulse decreases and combustion temperature decreases. And the smaller the plasticizing ratio is, the larger the decreasing amplitude will be. The content of GAPA and GAP has little effect on the smoke signature of the propellant. Replaced ammonium perchlorate (AP) with 4, 4-dinitro-3, 3-diazenofuroxan(DNAF), when the content of solids is 60%, and the theory specific impulse is 2600 N·s·kg^-1, compared with the combustion products of AP formulation, the combustion products of GAP/NC propellant don't contain HCl, while the content of N₂ increases by 44% and the content of Al₂O₃ decreases by 67%, indicating that GAP/NC propellant is a prominent propellant with high energy and low characteristic signal.