Abstract: Milk protein is an important component in milk and dairy products, and its content and composition are important factors influencing the functionality of milk such as nutrition and immunity. Protein components in milk are complex, and the content of different components varies greatly. With the development of functional properties of milk protein, it is of great significance and value to determine the content of milk protein components in a faster and more accurate way. Currently, enzyme-linked immunosorbent assay (ELISA), capillary electrophoresis (CE), high performance liquid chromatography (HPLC) and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) are the main methods used to determine protein components in milk. In this article, the measurement principle, applicability, and the characteristics of these methods are reviewed, which could provide reliable technical reference for accurate measurement and establishment of a novel method in milk protein evaluation, while this could also be a theoretical support for dairy nutrition research, development of dairy products and infant formula optimization.