This article examines the mechanisms through which authorship is both diminished and reconfigured in the production of AIGC films. In the context of generative artificial intelligence becoming deeply embedded in film production, the traditional conception of the author is weakened at the technical level. Yet within institutional mechanisms such as festival labeling, platform distribution, and cultural evaluation, authorship is reactivated as a central structure for attributing meaning and identifying stylistic coherence. Drawing on film-text analysis and critical discourse analysis, the article argues that creative intention in AIGC films is often carried by constructed agents such as models, platforms, or prompt engineers. This produces a tension in which technical decentering and cultural recentralization coexist. Building on this observation, the article proposes a re-attribution mechanism as a theoretical framework for understanding authorship in the AIGC era. It calls for moving beyond the binary opposition between author and non-author and for attending to the processes through which algorithms, institutions, and culture jointly construct meaning.