The invention discloses a device for reducing the wire jumping rate of silicon rod cutting and a cutting method. The device comprises a slicing machine body and an air pipe assembly, main rollers are symmetrically arranged on the slicing machine body, a fragment groove is formed between the two main rollers, a small roller is arranged below the fragment groove, and diamond wires are distributed on the main rollers and the small roller; the air pipe assembly is arranged below the main roller, the air outlets are formed in the two sides of the air pipe assembly, when the branch air pipes supply air, the symmetrical air knife-like design is formed, air flow periodically cleans the wire groove of the main roller in the rotating direction of the main roller in the cutting process, silicon powder and other foreign matter are prevented from being accumulated in the wire groove, and the service life of the wire groove is prolonged. According to the diamond wire cutting method, the risks of wire jumping and even wire breaking caused by the fact that the diamond wire is extruded out of a wire groove by foreign matter during high-speed cutting are avoided, the hidden danger of wire breaking caused by groove body defects is effectively made up when the diamond wire becomes thinner and thinner, and in the cutting method, points where impurities are likely to accumulate and become the hidden danger are cleaned in a targeted mode; and the influence on the diamond wire in the cutting process is avoided.