In order to investigate the combustion performance of four-hole cuboid gun propellants, a combustion physical model was established according to the structural characteristics of four-hole cuboid gun propellants. The Ψ-Ζ and Γ-Ψ curves were obtained through the Maple software. The theoretical combustion properties of four-hole cuboid gun propellants were compared with that of the cylindrical seven-hole and single-hole gun propellants under the same web size and length-to-diameter ratio. Meanwhile, the web size, length-to-diameter ratio and inner-hole diameter were researched as the main factors to the theoretical combustion properties. The results demonstrated that the four-hole cuboid gun propellant performed a good progressive combustion property when the length-to-diameter ratio was higher than 1.5, which was better than the cylindrical single-hole gun propellants. Although the four-hole cuboid gun propellant performed a worse combustion property than the cylindrical seven-hole gun propellant, it displayed the combustion split points in the latter point. Meanwhile, the four-hole cuboid gun propellant had a better progressive combustion property when the inner web size was the same as the outer, the length-to-diameter ratio was in the range from 1.5 to 3, and the inner-hole diameter was in the range from 0.10 mm to 0.20 mm. The experimental results agreed well with the theoretical analysis results, but the moulding process leaded to the certain deviation of inner hole, resulting in the splitting point reached in advance.