The invention discloses an improved anti-breakoff feeding system for a polishing machine. The improved anti-breakoff feeding system comprises a rice cooling bin, the polishing machine and a screw conveying device. The screw conveying device is arranged between the rice cooling bin and the polishing machine. A main discharging opening is formed in the discharging end of the rice cooling bin. A main feeding opening is formed in a feeding hopper of the screw conveying device. The main discharging opening communicates with the main feeding opening through a main pipeline. At least one pre-storage discharging opening is formed in the discharging end of the rice cooling bin. A pre-storage feeding opening is formed in the feeding hopper of the screw conveying device. The pre-storage feeding opening communicates with the pre-storage discharging opening through a pre-storage pipeline. A solenoid valve is arranged at each pre-storage feeding opening. A discharging opening of the screw conveying device communicates with a feeding opening of the polishing machine. By the adoption of the improved anti-breakoff feeding system, the situation that materials are run out when the polishing machine operates can be avoided, the production efficiency of rice is improved, the waste of resources is avoided as well, the production cost is lowered, meanwhile it can be guaranteed that the amount of rice flowing into the polishing machine is the same each time, and the service life of the polishing machine is prolonged.