Abstract: The width of the W-flame boiler furnace is large, and the secondary air of the large bellows structure is prone to uneven air distribution, resulting in local oxygen deficiency in the furnace and deviation of the water wall temperature, which cannot be solved by means of operation adjustment. According to the test results, the bellows structure was optimized and transformed, and the air distribution was carried out by means of partition control. Through the adjustment test of the modified bellows, the CO content in the furnace is greatly reduced, and the boiler efficiency and unit economy are effectively improved; the air distribution mode of "front wall pressing the rear wall" for the secondary air is realized, which increases the adjustment means of operators and effectively controls the wall temperature deviation.。