Based on artificial intelligence and big data, digital identity pushes the construction and identity of self and others in social relations to an unprecedented challenging situation. Different from natural identity, the relation pattern of digital identity is not just invisible, or the internal relation form established solely based on personal feelings or the entity label formed by others' judgment. Digital identity, as an individual action track, is presented in time and space dimensions, showing the relation pattern of individual action. In the face of these challenges, we need to go back to the source of identity construction to analyze whether digital identity has broken through or changed the natural identity construction system, therefore, it is inevitable to study the relation generation basis of digital identity construction from the philosophical foundation. Firstly, this paper reviews the concept and development of digital identity and natural identity, and points out that the similarity of digital identity and natural identity is the collection of personal information. Digital identity is a strengthened version of natural identity's collection of personal information. Traditional interpersonal communication and identity evaluation rely on individuals' integration of partial characteristic information of others, while digital identity directly presents all information of individuals. The difference lies in the different ways of presenting identity relations. Digital identity is presented as a kind of resource, while natural identity is more presented as a relation in life practice, which is manifested in different ways of production, meaning and identification. This paper analyzes the two relation forms of digital identity construction from the perspective of contrast between Chinese and Western philosophy, and points out that situation and reason are the basis of the relation form of Chinese and Western digital identity, but they do not indicate the position of relation in identity construction. Both Chinese and Western identity construction pay attention to the basis of relation form, but the emphasis of identity dimension is different. There are three dimensions in the form generation of digital identity relations: integration, reciprocity and pluralism. Digital identity relations show immanence, externality, ubiquity and dynamics, which explains the receptive problems faced by digital identity and the reasons why digital identity poses challenges to social relations. From the perspective of application, it is pointed out that digital identity is beneficial to the preservation of individual relation network information and the optimal management of social relation, but also brings the alienation of individual relation and the breakdown of social relation. The limit of the development of digital identity should be judged by maintaining the relation of natural identity. For digital security, we can guarantee the security of digital identity by providing two main paths: independent construction and complete preservation. Compared with previous literature, this paper makes further expansion in the following three aspects: firstly, different from the traditional Western identity division into rational relations, Chinese identity division falls into emotional relations. This paper points out that both Chinese and Western identity divisions pay attention to the interaction of emotion and reason, but the generation of relation is based on emotion as a transcendental logic or reason as a transcendental logic. Emotion-based identity construction emphasizes the separation of affinity and estrangement, social identity and relation priority, while reason-based identity emphasizes the internal logical relation, self-identity and entity priority in identity construction. Secondly, it pays more attention to the generation process and characteristics of digital identity from the perspective of identity generation and development, and finds out the presentation rules and reception differences of digital identity construction in Chinese and Western cultures, so as to point out the advantages and disadvantages as well as limits of digital identity development. Thirdly, it analyzes the commonality and individuality of digital identity and natural identity, and the limit of the development of digital identity should be judged by the relation between the maintenance of natural identity. Digital identity will gradually become a part of life, and the relation basis of identity is a process of gradual generation. It is necessary to explore the new digital identity constructed on the basis of humanistic care and the construction of new social relations involved in digital identity. To some extent, the research of this paper reveals different internal logical and philosophical roots of the application scopes, ways and reception degrees of digital identities in China and the West, which is conducive to a clearer understanding of the connotation, characteristics and future development trend of digital identities, and helps to prevent the arbitrary change and abuse of digital identities in the application process. It provides suggestions for government departments to manage and use digital identities more reasonably and efficiently in the future, and suggestions for laws, technology research and development related to digital identities as well. [ABSTRACT FROM AUTHOR]