To simulate the combustion property of seven-hole variable burning rate gun propellant, a combustion model of seven-hole variable burning rate gun propellant was established.On the basis of the geometric combustion law, the function relation of combustion gas generation brisance(Γ)against the percentage of gun propellant burned(Ψ) was deduced.The Γ-Ψ curves were obtained by programming and calculation.The effects of burning rate ratio, inner pore diameter of the fast burning layer, length-to-diameter ratio and thickness of the slow burning layer on the combustion progressive property of seven-hole variable burning rate gun propellant were analyzed.Results show that the seven-hole variable burning rate gun propellant under the following conditions has better combustion progressive property:the burning rate ratio of the fast burning layer to slow burning layer in 1.5-2.5, length-to-diameter ratio ranging from 2 to 3, the thickness ratio of slow burning layer and fast burning layer in the range of 0.1-0.22, and the inner pore diameter of the fast buruing layer ranging from 0.2 mm to 0.3 mm.