The cognitive difference of the development level of artificial intelligence technology and the different understanding of the work concept connotation in the copyright law lead to the multiple judgment of content attribute generated by artificial intelligence. Although the content generated by artificial intelligence falls easily into the category of literature, art and science in form, and can be reproduced in tangible form. However, according to the philosophical views of Kant and Marx, artificial intelligence is not a rational person with in-itself purpose. It can only be the object of human labor reform, and can only exist in the form of objects. It cannot have thoughts and emotions like human beings. The AI-generated content does not conform to the originality standard of works and cannot be classified as works in law doctrine. However, in order to realize multiple values in the cultural market, the content that conforms to the original "objective standard" must be made into works. The viewpoint of ownership of AI-generated content belongs to the logic justification of norm level, which is suspected of arrogation of copyright law. On the premise of ensuring the "right of discourse" in copyright law, the "signatory" should be identified as the owner of the content to ensure the balance of interests.