Abstract: Maize is an important grain-forage crop with rich protein content in grains. It can not only supplement human dietary nutrition, but also improve feed value and reduce breeding costs. However, its grains are low in essential amino acids such as lysine and tryptophan, which restricts its dual value as food and feed. Quality protein maize (QPM) can accurately increase the level of essential amino acids, providing an effective solution for improving dietary quality in malnourished areas and raising feed conversion efficiency. This paper reviews the genetic basis of quality protein maize, systematically summarizes the research progress in major breeding strategies including conventional breeding, marker-assisted selection, genomic selection and gene editing, clarifies the core challenges such as the negative correlation between yield and protein content and limited genetic diversity, and proposes future development directions combined with the trend of cutting-edge technology.