Milk is an important allergic food for infants and children, and there are significant differences among different individuals, depending on age, race and environment. The main allergens of milk were casein, α-lactalbumin, β-lactoglobulin and P1 component with higher molecular weight. These four components can react with allergic serum, and the detection methods include electrophoresis, chromatography, enzyme-linked immunoassay (ELISA), sensors, proteomics based on mass spectrometry (LC-MS/MS), polymerase chain reaction technology (PCR), etc.