The invention discloses a steam recycling system for a corrugated paper board production line. The steam recycling system mainly solves the technical problem that the temperature of steam output fromthe interior of a first-level preheating cylinder is too high, and consequently, the subsequent product quality is lowered. According to the technical scheme, the steam recycling system is characterized by comprising a steam furnace and a main steam outlet pipe connected with the steam furnace, the main steam outlet pipe is connected with a tile wheel roller, a first-level preheating cylinder matched with a single tile machine, and a second-level preheating cylinder matched with a paper pasting machine, wherein the tile wheel roller, the first-level preheating cylinder and the second-level preheating cylinder are sequentially connected in series; the second-level preheating cylinder is connected with a main steam return pipe connected with the steam furnace, and an adjusting device for adjusting the temperature of the steam entering the second-level preheating cylinder is connected between the first-level preheating cylinder and the second-level preheating cylinder. The adjusting device can adjust the temperature of the steam entering the second-level preheating cylinder. When it is found that the temperature of the steam is too high, the adjusting device can reduce the temperatureof the steam, the situation that after the water in paper boards is excessively evaporated, the bonding effect is not good is avoided, and the product quality is guaranteed.