Provided is a watermarking embedding and authentication method of positioning PDF electronic invoice falsification, comprising: A, watermarking generation based on a file reading page, concretely including blocking a reader page, parsing a code page file structure, generating authentication information, and generating watermarking in dependence on the authentication information; B, watermarking embedding based on file codes; C, updating of a cross reference and an end-of-file; and D, generation of a PDF electronic invoice file with watermarking, including performing E authentication information reconstruction, authentication information extraction and F falsification authentication on a PDF electronic file to be detected, and F falsification authentication including falsification authenticity determination and falsification positioning and marking. The method can guarantee invisibility of watermarking, and meanwhile control file increment within 1%. The method has the characteristics of high falsification detection accuracy, and low false drop rate, and can effectively resist replacing, adding, deleting, etc.