The invention provides a method for adding and recognizing a watermark to a document in the printing process. The method for adding and recognizing a watermark to a document in the printing process comprises the following steps: S1, receiving the data ransferred from an office software: the printing system receives the data ransferred from the office software; S2, adding a watermark: the printing system adds the watermark to the data transferred from the office software combining with the binarized watermark information, and completes the printing work; S3, recognizing the watermark: combining the matrix obtained from a paper watermark document scanning piece with the matrix obtained according to the data transferred from the office software, and integrating an intermediate transformation matrix, and restoring the watermark information according to the intermediate transformation matrix and the hash matrix of watermark adding. The invention provides the method for adding and recognizing a watermark to a document in the printing process, and according to the invention, the watermark information is binarized, therefore, the added watermark information is knowable and difficult to read, has a strong anti-interference ability, and has the functions of protecting the enterprise information and the copyright of the document more effectively, etc..