The study of β-decay is a process of investigating the deep physical principles of matter, which began with the study of β-radiation, and led people's understanding of matter from the level of atoms to the level inside nuclei. The measurement of its energy spectrum led to Pauli's neutrino hypothesis. On this basis, Fermi proposed the first phenomenological theory of beta decay and introduced the concept of weak interactions. After that, the development of intermediate boson theory of weak interactions led people's understanding of matter to the level deep inside nucleons, promoted the development of the unified electroweak theory and finally the completion of the Standard Model. This article reviews the important physics event of β-decay throughout the 20th century, analyses and introduces the key events in the history of study of β-decay, which are important for understanding the construction and development of the standard model in modern physics.