The invention relates to an anti-scorching device with an air volume self-adaptive adjusting function. The anti-scorching device comprises an anti-scorching air blocking piece, a secondary air nozzleand a windbox. One side of the windbox is provided with the secondary air nozzle. The bottom surface or the lateral side of the secondary air nozzle is provided with an anti-scorching air outlet. Theanti-scorching air blocking piece is arranged at an outlet of the anti-scorching air outlet and is of a bimetallic structure. One side, close to the air, of the anti-scorching air blocking piece is ametal piece with a smaller coefficient of thermal expansion, and the side, close to boiler flame, of the anti-scorching air blocking piece is a metal piece with a large coefficient of thermal expansion. The anti-scorching device with the air volume self-adaptive adjusting function has the beneficial effects that the anti-scorching air blocking piece is of the bimetallic structure with different thermal expansion coefficients, air volume adjusting is achieved by virtue of the deformation of the bimetallic piece, and the air volume of anti-scorching air is adaptively adjusted along with the temperature change near a burner nozzle. When the temperature near the nozzle is low, the anti-scorching air volume is very small. When the temperature near the nozzle is high, the anti-scorching air volume is increased. The anti-scorching device is simple and reliable in structure, does not need additional measurement and feedback components, does not have the phenomena of jamming and the like, and is low in cost.