The invention provides a fast separation and detection method for whey protein components in a dairy product. The method comprises the following steps: 1 preparing a standard solution or unfreezing the standard solution; 2 preparing a sample solution to be detected; 3 conducting HPLC separation and detection, wherein the standard solution and the sample solution to be detected are separated through gel chromatography columns. According to the method, firstly, a dairy product and/or a standard product to be detected is dissolved or diluted with a phosphate buffer solution; then all types of protein components are separated through the gel chromatography columns and detected through an ultraviolet detector or a diode array detector, and through the comparison with the peak area of the standard area, the content of each type of whey protein in the dairy product is calculated out. When the detection method is used to detect the whey protein in the dairy product, the detection is fast, the operation is simple and convenient, and the reproducibility is good.