A new seraph star-hole stick gun propellant with large web size was designed and prepared. The combustion characteristics of the star-hole stick gun propellants with different ratios of length to diameter(L/D=1, 2, 6) and different sealing layer thicknesses/gun propellant web size ratios (s/e₁=0, 0.05, 0.1) were studied by closed bome and combined with a large caliber gun, the experimental verification was performed. Results show that the combustion of the star-hole propellant is stable, revealing a parallel layer combustion. When the L/D increases from 1 to 6, the progressive combustion factor P_r increases by 56.8% from 0.285 to 0.447, and the maximum pressure point delays. The L-B curves of end plane plugging propellants display obvious low initial combustion activity and hole breaking combustion. When the s/e₁ increases from 0 to 0.05 and 0.1, the initial gas generaation quantity of the star-hole stick gun propellant were reduced by about 1/2, and the hole breaking times were between the burning time needed to burn 10% to 20%(burned fraction) propellants. Selecting appropriate thicknesses of the plugging layers can realize the controllable regulation of the gas generation law of the propellants.When the s/e₁ increases from 0 to 0.05 and 0.1, the maximum bore pressure p_m decreases by 1.39% and 3.59% respectively, however, the initial speed of projectile at 32.5 m from gun muzzle increases by 0.28% and 1.4%, respectively.