Al powder,RDX and catalysts was coated by nitrocellulose and formed composite spherical green powder. The modified double-based propellant product was produced by the composite spherical green powder. The effects of the composite spherical green powder on mechanical and combustion properties of formed propellant were studied. Results show that their mechanical properties are much better than that of double-based spherical green powder made propellant. Their low temperature elongation at break from is increased from 7.84％ to 26.86％,the max ensile strength at high temperature is close to double increase,and the temperature pressure index is decreased from 0.38 to 0.30. 