The corrosion behavior of 12Cr1MoVG tube in a waste incineration boiler superheater was investigated using on-site and laboratory testing. Low-melting-point ZnCl2 and PbCl2 induced the formation of eutectic mixtures. These eutectic mixtures captured ash particles, resulting in severe slagging on the 12Cr1MoVG tube. The structure of the oxide layer on the 12Cr1MoVG tube was severely disrupted by the high S and Cl contents in waste fuel. Under the influence of brittle Fe2O3 and FeS spalling, FeCl2 dissolution, FeCl3 and FeSO4 volatilization, and severe internal oxidation, corrosion perforation appeared in the 12Cr1MoVG tube.