Selenium as an essential trace element is widely found in living organisms. Selenoprotein is the main carrier of the physiological function of selenium in organism. Selenoprotein is a type of protein containing selenocysteine located at the redox catalytic site. Therefore， it has a higher redox potential， and selenoprotein is also mainly used as oxidase in plants and animals. It has the characteristics of maintaining cellular regulatory oxidative stress， immune function， endoplasmic reticulum stress， and inflammatory response， and has therapeutic and preventive effects on many diseases such as Keshan disease， cancer， and Alzheimer's disease. In this paper， the metabolic pathways of selenium protein， the synthesis mechanism of selenium protein and its physiological function characteristics are reviewed in order to provide reference for the study of selenium protein.