The invention relates to a method for measuring content of IgG (immunoglobulin G) in pig plasma protein powder. The method comprises the following steps of (1) sampling: weighing the pig plasma protein powder and adding into an extracting solution, so as to obtain the to-be-detected sample; (2) constant-temperature extracting: putting the to-be-detected sample into a constant-temperature rocking bed or an oscillation culture box, extracting, centrifuging, and filtering, so as to obtain the to-be-detected liquid; (3) detecting the to-be-detected liquid by high performance liquid chromatography.Compared with the prior art, the method has the advantages that the extracting effect is better, the accuracy of measuring result is high, the data stability is good, the operation is rapid, the linear relationship is good, and the method is suitable for being popularized and applied.