The invention discloses a control system of a circle cutting machine. The round cutting machine comprises a machine frame base, a machine frame arranged on the machine frame base, rolling ball lead screws, a foam passing roller, a foam conveying roller, a foam conveying motor, a driving cutter wheel, a driven cutter wheel, a cutter belt and a large belt wheel, wherein the machine frame is arranged on the machine frame base, the rolling ball lead screws are arranged at the left end and the right end of the machine frame base, the foam passing roller is arranged between the rolling ball lead screws and is used for installing round foam, the foam conveying roller is used for driving the round foam to rotate, the foam conveying motor is used for driving the foam conveying roller to rotate, the driving cutter wheel and the driven cutter wheel are arranged at the two ends of the machine frame base, the cutter belt is arranged between the driving cutter wheel and the driven cutter wheel and is used for cutting the round foam, and the large belt wheel is connected with the driving cutter wheel and the driven cutter wheel. The control system has the advantages that the production efficiency can be greatly improved, the product precision is improved, the operation is simple, the labor consumption is low, the round foam only needs to be manually supported on the rolling ball lead screws through the foam passing roller during the feeding, and the labor is not needed in the foam cutting process; the foam cutting precision of the circular cutting machine is greatly improved, and the smallest slice thickness can reach 1.5mm.