Subjectivity is an important perspective to observe the relationship between man and technology. From instrumentalism to ontology and subjectivism of technology, this relationship is being constantly rewritten. Based on the concept of technological subjectivity, post-humanism re-activates the concept of subject with the post-human subject image represented by cyborg, in order to break into the theoretical space of cultural and political criticism. The new subject created by technology and its practice innovate the production mechanism of meaning, such as identity, recognition, and value, providing a powerful momentum for deconstructing the various hegemonic systems lurking in traditional humanism. However, as the subject of cyborg is conceptualized as a signifier or discourse, it eventually evolved into a resurgence of the technical myth. The limit of post-humanism is manifested in three aspects: the loss of focus of the theory of disembodiment, the elimination of the alienation narrative based on technical ontology, and the lack of critical dimensions in technical and political practice. These limits weaken and deconstruct the critical function of the concept of post-human subjectivity. Post-humanism needs to return to practice and to reinvestigate the relationship between technological and human subjectivity from historical and structural perspectives, in order to establish a dialectical theory of post-human subject and to effectively promote the historical agenda of "rewriting modernity" that is based on the imagination of the relationship between human and technology.