As one type of articles, document writing is asked to follow the laws of articles and writing. Whether from the view of the dynamic writing process or the static text analysis, document writing is permeated inevitably by the writer's moderate emotion. As intrinsic sign of aesthetic characteristics of document writing, the writer's moderate emotion with materials, finally, becomes the specific and perceptible extrinsic images which we can call“Implied Author”(the concept was proposed by Wayne Booth). The implied author has overall power for the document writing, leads the readers, contains the emotional tendencies and ideological tendencies of the agencies and writers, and it can be felt by readers when they read the document. It is extremely good for expression of document writing when writers grisp the image of the implied author