The annual consumption of the grate bar of sintering machine in China is large, and the important reason for its failure is corrosion. In this paper, the physical and chemical characteristics of failed grate bar are systematically studied, the causes of corrosion failure are analyzed, and the influence of waste reuse on corrosives emission is discussed. The results show that, according to the main chemical components and structural characteristics, the failed grate bar can be divided into adhesion layer, corrosion layer and metal layer from the surface layer to the inner layer, among which; the main components of the adhesion layer are Fe, K, Cl, S and Ca, and the structure is relatively loose. The main components of the corrosion layer are Fe, O and Cr, of which Fe2O3 has a loose structure and Cr₂O₃ has a dense structure; the main components of the metal layer are Fe and Cr, and the structure is dense. The main reasons for the corrosion of the grate bar; under the comprehensive action of fume high temperature, alkali metal salt, SO₂, etc., chlorine corrosion, sulfate corrosion and high temperature oxidation corrosion occur in the grate bar. Reducing solid waste elements with a high mass fraction and wastewater reuse is conducive to reducing the generation and discharge of corrosives, which is the key to control grate bar corrosion.