Authenticity is always the first essence of documentary, "whether to use natural materials" is the boundary between documentary and feature film, so documentary is the first principle of authenticity. On this basis, the story is "creative treatment of reality", which is the necessary means for natural materials to fully show the truth. "Documentaries can and should take all fictional means and strategies to achieve reality." [3] In the second season of the world of man, the director uses the narrative method of combination of documentary and storyThe film has more real charm.