Abstract: The boiler water wall tube in an industrial park's own power plant perforated for many times during operation. The causes of perforation on water wall tube were analyzed by means of inner wall scale analysis and metallographic examination, combined with the field conditions. The results show that the conductivity and SiO₂ content of water in boiler were high, and there was no on-line instrument monitoring in the field, which led to the alkali corrosion under the scale, resulted in the tube wall thinning to unable to bear the stress and the perforation and burst.