The invention relates to an automatic writing method based on an extraction type multi-document abstract method, which comprises the following steps of A1, user input and data preprocessing of receiving a keyword inputted by a user, retrieving the related data on a data retrieval platform, and performing the preliminary processing on the retrieved related data; A2, graph sorting of inputting a plurality of documents, firstly identifying all sentences by the system, and scoring the importance of all the sentences; A3, redundancy removal of if two or more sentences with the similarity exceedinga preset threshold exist in the sentences, only reserving one sentence, and outputting an ordered sentence list with redundant sentences removed; and A4, constructing and outputting, selecting the most important sentences from the ordered sentence list provided in the previous stage according to the limitation of the text from front to back, reordering the sentences, and outputting a manuscript formed by the ordered sentences.