The invention discloses a portable electronic readingand editing device and a documentediting method thereof. The document editing method of the portable electronic reading and editing device comprises the steps that a plurality of first pages of a first document are displayed in a page directory display area, a plurality of second pages of a second document are displayed in an overview display area, at least one first page of the first document is moved to the overview display area, and the at least moved one first page is saved in the second document. The portable electronic readingand editing device comprises the page directory display area, the overview display area, a control input module and a computation and storage module. According to the portable electronic reading and editing device and the document editing method thereof, the documentediting function is further enriched, and the effect and the performance are better.