In order to study the influence of aluminum powder on the mechanical property， interface， combustion， safety， energy， density and other performance of propellants， the glycidyl azide polymer （GAP） propellants with 5%， 10%， 15% and 18% aluminum powder were evaluated by tensile testing machine， dynamic thermomechanical analysis （DMA）， calculation program and etc. Results show that， with the replacement of 320 μm AP with 30 μm aluminum powder and the increase of aluminum powder contents， the propellant has increasing maximal tensile strength and maximal elongation， and improving interface performance. The burning rates change scarcely but the pressure indexes drop down from 0.43 to 0.40 under the pressure of 3-9 MPa. The hazard grades of propellants with 5% and 18% aluminum powder are 1.3 both. The impact and friction sensitivities of propellant with 18% aluminum powder are 0% and 44%， respectively， which are lower than the formulation with 5% aluminum powder （4% and 48%， respectively）. At last， the calculation result shows that with the increase of aluminum powder， the energy and density of propellants grow up， but the standard specific impulse levels off to moderate pace of growth.