Nowadays, cases of abuse and misuse of information technology are not uncommon, causing many negative effects and social problems that are extremely harmful to people, such as Internet fraud and cyberbullying. Practice all over the world shows that enhancing digital citizenship is an effective way to solve these problems. In order to call for emphasis on digital citizenship, this paper discussed its theoretical basis and training system in detail. Specifically, it firstly defined the concept of digital citizenship, then comprehensively discussed the content of digital citizenship through literature research, which constituted four first-level content indicators and eleven sub-indicators. After clarifying the connotation and extension of digital citizenship, this paper continued to discuss its uniqueness and irreplaceability, so as to highlight its necessity. Then the importance and meaning of implementing digital citizenship education were stated respectively. Based upon this theoretical foundation and our national conditions, a three-oriented digital citizenship training system was finally proposed. The cultivation of qualified digital citizens is imperative, as it helps to enhance the overall improvement of core literacy and Digital Intelligence Quotient, and facilitate the construction of a civilized and harmonious digital society and the achievement of Lide Shuren goal as well.