With autism (Autistic disorder), the patients will appear phenomenon like language disorder, communicating disorder and social disorder who are mostly two or three-year-old boy. Once the diagnosis confirmed, a lifelong bothering would be caused to the patients and their family. A novel hypothesis for the pathogenesis of autism which is called Double Mirror Reflection Model (DMRM) is put forward combined with the current brain science developments by this paper. The camera-monitor experiments explains the content of the hypothesis. With this paper, a new thinking is provided to the precaution and the diagnosis for autism.