Maize is an important food crop that is primarily used as feed to provide necessary metabolizable energy and nutrients for livestock and poultry. The nutritional value of feed is closely associated with the proportion of protein and amino acid composition.However，maize protein exhibits an imbalanced amino acid content，adding soybean meal supplements the lysine and tryptophan lacking in maize. However，sulphur-containing amino acids （cysteine and methionine） are also limiting amino acids in soybean. Methionine has a direct effect on the rate of protein synthesis in the bodies of livestock and poultry，which in turn affects the production of meat，eggs，and milk. Consequently，it is of great importance that there be a significant enhancement of the sulphur-containing amino acid content，particularly that of methionine，in maize，with a view to facilitating the development of animal husbandry. One limitation of China's maize germplasm resources is the lack of high methionine varieties. Additionally，the breeding process is relatively slow. In recent years，extensive research has been conducted on the absorption and transport mechanism of sulfur elements in plants，leading to the initial construction of a metabolic regulatory network for sulfur-containing amino acids. In this study，we summarized the research results of improving the metabolic mechanism of sulfur-containing amino acids in crops，proposed a new strategy of combining population genetics，comparative genomics and molecular biology to mine candidate genes，and used modern biological breeding to improve the methionine content of maize，so as to provide a reference for genetic improvement of high-quality protein maize.