Abstract: A fast, batch and non-invasive identification and screening method of cows with A2 ?-casein genotype of producing A2 milk belongs to the cow genotyping field and includes steps of: 1) collecting milk samples of cows; 2) detecting and acquiring mid-infrared spectral data; 3) data preprocessing to remove outliers; 4) dividing the dataset after the preprocessing into a training set and a testing set according to random sampling principle; 5) screening modeling spectral wavebands; and 6) combining different spectrum preprocessing methods with a modeling algorithm to establish classification models, using accuracy, sensitivity, specificity and AUC to evaluate the models, and determining the best classification model. The method can realize rapid and batch identification of cows of producing A2 milk and non A2 milk, and may have advantages of fast, high precision, low cost, simple operation, batch determination, no trauma (no blood collection, hair plucking, and tissue extraction), and strong practicability.